U.S. patent application number 13/740674 was filed with the patent office on 2013-05-30 for apparatus and method for displaying document.
This patent application is currently assigned to SAMSUNG ELECTRONICS CO., LTD.. The applicant listed for this patent is SAMSUNG ELECTRONICS CO., LTD.. Invention is credited to Myung-jae Kim, Jeong-ho Nho, Ki-hong Park.
Application Number | 20130139054 13/740674 |
Document ID | / |
Family ID | 42668739 |
Filed Date | 2013-05-30 |
United States Patent
Application |
20130139054 |
Kind Code |
A1 |
Kim; Myung-jae ; et
al. |
May 30, 2013 |
APPARATUS AND METHOD FOR DISPLAYING DOCUMENT
Abstract
Provided are an apparatus and method for displaying a document,
the document display apparatus including an image processor which
displays a document including a plurality of pages; a memory unit
which stores individual unit elements constituting the document and
image data including the individual unit elements; and a controller
which controls the image processor to generate the image data
corresponding to at least one page estimated to be turned to among
the plurality of pages, store the image data in the memory unit,
and display the image data corresponding to a requested page among
the stored image data when a user requests a page transition. With
this, the page transition speed may be improved through image
caching.
Inventors: |
Kim; Myung-jae; (Suwon-si,
KR) ; Park; Ki-hong; (Seoul, KR) ; Nho;
Jeong-ho; (Suwon-si, KR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
SAMSUNG ELECTRONICS CO., LTD.; |
Gyeonggi-do |
|
KR |
|
|
Assignee: |
SAMSUNG ELECTRONICS CO.,
LTD.
Gyeonggi-do
KR
|
Family ID: |
42668739 |
Appl. No.: |
13/740674 |
Filed: |
January 14, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
12766587 |
Apr 23, 2010 |
8365073 |
|
|
13740674 |
|
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Current U.S.
Class: |
715/273 |
Current CPC
Class: |
G09G 2360/121 20130101;
G09G 2320/0252 20130101; G09G 2380/14 20130101; G09G 5/39 20130101;
G06F 40/103 20200101 |
Class at
Publication: |
715/273 |
International
Class: |
G06F 17/21 20060101
G06F017/21 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 7, 2009 |
KR |
10-2009-0061731 |
Claims
1. A document display apparatus comprising: an image processor
which displays a document comprising a plurality of pages; a memory
unit which stores unit elements of the document and a plurality of
image data comprising the unit elements; and a controller which
controls the image processor to generate a first image data
corresponding to at least one page estimated to be selected from
among the plurality of pages of the document, store the generated
first image data in the memory unit, and when a page transition is
requested by user and selects the estimated page of the document,
controls the image processor to display the selected page of the
document using the first image data stored in the memory unit,
wherein the controller controls the image processor to sequentially
generate the first image data in order of neighboring a currently
displayed page, wherein the first image data is alternately
generated in directions of a subsequent page and a previous page
with respect to the currently displayed page; and wherein the
controller controls the image processor to prioritize the unit
elements based on a user's selection.
2. The document display apparatus according to claim 1, wherein the
controller controls the image processor to generate and display a
second image data corresponding to the requested page if a first
image data corresponding to the requested page is not stored in the
memory unit.
3. The document display apparatus of claim 2, wherein the memory
unit additionally stores a memory map, the memory map comprising a
plurality of addresses corresponding to the plurality of second
image data.
4. The document display apparatus of claim 3, wherein a number of
the plurality of second image data corresponds to neighboring pages
of the current page, in accordance with an estimated page turn of
the current page and the number of the plurality of addresses of
stored image data.
5. The document display apparatus of claim 4, wherein the
controller controls the image processor to sequentially generate a
predetermined number of second image data corresponding to
neighboring pages of the current page, in accordance with said
estimated page turn and a predetermined number of the plurality of
addresses of second image data, said sequence based on a page
distance from the current page.
6. The document display apparatus of claim 4, wherein the
controller controls the image processor to sequentially generate
second image data corresponding to additional subsequent pages, in
accordance with said estimated page turn and a remaining number of
the plurality of addresses of second image data, said sequence
based on a page distance from the current page.
7. The document display apparatus of claim 4, wherein if the
requested page turn does not correspond to the estimated page turn
of the current page, the controller controls the image processor to
compare the plurality of second image data to an updated estimated
page turn.
8. The document display apparatus of claim 7, wherein the image
processor, based on the comparison, generates updated image data in
accordance with the updated estimated page turn, and selectively
deletes second image data that is not in accordance with the
updated estimated page turn.
9. The document display apparatus of claim 7, wherein, based on the
comparison, the image processor updates the addresses of said
memory map to correspond to the updated image data and the updated
estimated page turn.
10. The document display apparatus of claim 1, further comprising:
a transition speed setting unit, wherein each of the plurality of
pages of the document comprises a plurality of image elements, and
wherein, in accordance with a transition speed, the controller
controls the image processor to generate the plurality of second
image data by selectively abstracting or excluding at least one
image element.
11. The document display apparatus of claim 10, wherein the
selective abstracting or excluding of at least one image element is
in accordance with a priority based on the effect of said image
element on delivering meaning of the corresponding page of said
image element.
12. The document display apparatus of claim 4, wherein the
controller controls the image processor to sequentially generate
said second image data, in accordance with said estimated page turn
and a number of the plurality of addresses of second image data,
wherein said sequence is based on a page distance from the current
page.
13. The document display apparatus according to claim 1, wherein
the controller controls the image processor to generate at least
one of the first image data by stepwise excluding unit elements
with a low priority, based on a page transition speed increase.
14. The document display apparatus according to claim 1, wherein
the first image data is alternately generated in directions of a
subsequent page and a previous page with respect to the currently
displayed page, within a predetermined range, and the first image
data is sequentially generated in the direction of the subsequent
page, with respect to the current displayed page, beyond the
predetermined range.
15. The document display apparatus according to claim 1, wherein
the controller generates the first image data and a memory map for
mapping a location where the first image data is stored, and stores
the first image data and the memory map in the memory unit.
16. The document display apparatus according to claim 15, wherein
the controller controls the image processor to generate the first
image data while excluding a previously stored image data
corresponding to the first image data, by referring to the memory
map.
17. The document display apparatus of claim 1, wherein said
generation of the first image data corresponding to the current
page comprises abstracting RGB data for a screen output.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This is a continuation application of U.S. application Ser.
No. 12/766,857, filed Apr. 23, 2010, which claims priority from
Korean Patent Application No. 10-2009-0061731, filed on Jul. 7,
2009 in the Korean Intellectual Property Office, the disclosure of
which is incorporated herein by reference.
BACKGROUND OF INVENTION
[0002] 1. Field of Invention
[0003] Exemplary embodiments consistent with the present invention
relate to an apparatus and method for displaying a document, and
more particularly to an apparatus and method for displaying a
document, which may improve a page transition speed through image
caching.
[0004] 2. Description of the Related Art
[0005] To directly open document files without conversion in a
display apparatus, a function of a document viewer has been widely
used. Also, a document viewer may be installed in general personal
computer (PC) environments and open the document files without
installing a document editor.
[0006] Recently, an embedded environment of a portable device such
as a mobile terminal, a personal digital assistant (PDA), a
portable multimedia player (PMP), etc. has tended to utilize a
document viewer having the same function as those of the PC
environment. Also, an electronic device such as a digital
television (TV), a projector, a camcorder, a camera, etc. may
require a document viewer.
[0007] The performance of the document viewer varies depending on
the embedded environment. For example, while a central processing
unit (CPU) may maintain the same performance, the performance of
the document viewer, i.e., a page transition speed, may become
lowered as an output resolution of a display apparatus increases.
Since the existing portable devices may support low display
resolutions of, for example, 320*240, 480*320, 800*400, etc., such
devices may be less restricted by the performance of the document
viewer, when using such low display resolutions. However, digital
TVs may support a full high definition (HD) of 1920*1080, and there
are projectors of various specifications that support resolutions
of, for example, 1024*768, 1280*1024 and full HD. Thus, if a
document viewer is installed in such a high resolution product, the
page transition speed may be considerably lowered. Accordingly,
there is required an apparatus and method for displaying document
files at high resolutions and improving the performance of the
document viewer by enhancing the page transition speed.
SUMMARY OF THE INVENTION
[0008] Exemplary aspects of the present invention provide an
apparatus and method for displaying a document, in which a page
transition speed may be improved by image caching.
[0009] The foregoing and/or other aspects of the present invention
may be achieved by providing a document display apparatus
comprising an image processor which displays a document comprising
a plurality of pages; a memory unit which stores individual unit
elements constituting the document and image data comprising the
individual unit elements; and a controller which controls the image
processor to generate the image data corresponding to at least one
page estimated to be turned to among the plurality of pages, store
the image data in the memory unit, and display the image data
corresponding to a page among the stored image data when a user
requests a page transition.
[0010] The controller may control the image processor to generate
and display the image data corresponding to the requested page if
the image data corresponding to the requested page is not stored in
the memory unit.
[0011] The controller may control the image processor to generate
the image data as a page unit.
[0012] The controller may control the image processor to generate
the image date by stepwise excluding the individual unit elements
having a low priority, as a page transition speed becomes
faster.
[0013] The controller may control the image processor to give a
priority to the individual unit elements according to effects on
delivering meanings of the document or based on a user's
selection.
[0014] The controller may control the image processor to
sequentially generate the image data in order of neighboring a
currently displayed page, so that the image data are alternately
generated in both directions of a subsequent page and a previous
page with respect to the current displayed page.
[0015] The controller may control the image processor to
sequentially generate the image data in order of neighboring a
currently displayed page, so that the image data are alternately
generated in both directions of a subsequent page and a previous
page with respect to the current displayed page within a
predetermined range and the image data are sequentially generated
in a direction of the subsequent page with respect to the currently
displayed page beyond the predetermined range.
[0016] The controller may generate the image data and a memory map
for mapping a location where the image data is stored, and stores
the image data and the memory map in the memory unit.
[0017] The controller may control the image processor to generate
the image data while excluding the previously stored image data by
referring to the memory map, if turning to the requested page.
[0018] The controller may update the memory map to correspond to
the image data generated in order of neighboring the requested
page, if turning to the requested page.
[0019] Another aspect of the present invention can be achieved by
providing a document display method comprising: generating image
data corresponding to at least one page estimated to be turned to
among a plurality of pages included in a document; storing the
generated image data; and displaying the image data corresponding
to a requested page among the previously stored image data if a
user requests a page transition.
[0020] The document display method may further comprise generating
and displaying the image data corresponding to the requested page
if the image data corresponding to the requested page is not stored
in the memory unit.
[0021] The document display method may further comprise generating
the image data as a page unit.
[0022] The document display method may further comprise generating
the image date by stepwise excluding the individual unit elements
having a low priority, as a page transition speed becomes
faster.
[0023] The document display method may further comprise giving a
priority to the individual unit elements according to effects on
delivering meanings of the document or based on a user's
selection.
[0024] The document display method may further comprise generating
the image data in order of neighboring a current displayed page, so
that the image data are alternately generated in both directions of
a subsequent page and previous page with respect to the currently
displayed page.
[0025] The document display method may further comprise
sequentially generating the image data in order of neighboring a
currently displayed page, so that the image data are alternately
generated in both directions of a subsequent page and a previous
page with respect to the currently displayed page within a
predetermined range and the image data is sequentially generated in
a direction of the next page with respect to the currently
displayed page beyond the predetermined range.
[0026] The document display method may further comprise generating
and storing the image data and a memory map for mapping a location
where the image data is stored.
[0027] The document display method may further comprise generating
the image data while excluding the previously stored image data by
referring to the memory map, if turning to the requested page.
[0028] The document display method may further comprise updating
the memory map to correspond to the image data generated in order
of neighboring the requested page, if turning to the requested
page.
BRIEF DESCRIPTION OF THE DRAWINGS
[0029] The above and/or other aspects of the present invention will
become apparent from the following description of exemplary
embodiments, taken in conjunction with the accompanying drawings,
in which:
[0030] FIG. 1 is a configuration of a document display apparatus
according to an exemplary embodiment of the present invention;
[0031] FIGS. 2A and 2B are exemplary embodiments of a memory
unit;
[0032] FIG. 3A is exemplary selection items for a page turning
speed function according to an exemplary embodiment of the present
invention;
[0033] FIG. 3B is an exemplary menu screen displayed when the speed
optimization function of FIG. 3A is selected, according to an
exemplary embodiment;
[0034] FIG. 4A is an exemplary page order of a document;
[0035] FIG. 4B is an exemplary embodiment of a memory map;
[0036] FIGS. 5A to 5C are exemplary views of a process of updating
a memory map, according to an exemplary embodiment of the present
invention;
[0037] FIGS. 6A to 6C are exemplary views of a process of updating
a memory map, according to another exemplary embodiment of the
present invention; and
[0038] FIGS. 7A to 7C are exemplary views of a process of updating
a memory map according to another exemplary embodiment of the
present invention.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS OF THE INVENTION
[0039] Exemplary embodiments of the present invention will now be
described in detail with reference to the accompanying drawings so
as to be easily realized by a person having ordinary knowledge in
the art. The present invention may be embodied in various forms
without being limited to the exemplary embodiments set forth
herein. Descriptions of well-known parts are omitted for clarity,
and like reference numerals refer to like elements throughout.
[0040] FIG. 1 is a configuration of a document display apparatus
according to an exemplary embodiment of the present invention.
[0041] A document display apparatus 100 in this embodiment may be
achieved by a projector, a digital TV, a PC, etc. Further, an
electronic device may be used as the document display apparatus
100, according to the present embodiment, if it has a document
viewer function capable of directly opening a document file without
conversion.
[0042] The document display apparatus 100 in this embodiment may
include an image processor 110, a memory unit 120, a controller
130, and a user input unit 140.
[0043] The image processor 110 may process and display a document
that includes a plurality of pages. In this case, the document may
be provided in the form of a document file having an extension
format such as *.DOC, *.PPT, *.XLS, *.PDF, *.HWP, *.TXT, *.HTML,
etc.
[0044] Specifically, the image processor 110 receives and parses a
document file in order to analyze information about the kinds,
positions, etc. of individual unit elements that constitute the
document. According to an exemplary embodiment, the individual unit
element may be an object. Individual elements may include, for
example, a text box, a picture box, a diagram, a word art, a VISIO
object, a table, a chart, etc.
[0045] The image processor 110 may perform a pretreatment
operation, e.g., parsing the analyzed individual unit elements,
giving priority to them, etc. In this case, the image processor 110
stores the abstracted individual unit elements in the memory unit
120 to be described later.
[0046] Then, the image processor 110 performs a page rendering to
display one page from the abstracted individual unit elements as an
image, and generates image data by abstracting RGB data for a
screen output from the rendering result. In this case, the image
processor 110 stores the generated image data in the memory unit
120.
[0047] Meanwhile, the image processor 110 may include a liquid
crystal display (LCD), an organic light emitting diode (OLED), a
plasma display panel (PDP), etc.
[0048] The memory unit 120 may store the individual unit elements
constituting the document, and may store image data which includes
the individual unit elements.
[0049] The memory unit 120 may be partitioned into a plurality of
regions or include a plurality of memories, which will be described
in more detail with reference to FIGS. 2A and 2B.
[0050] To improve a page transition speed, the document display
apparatus 100 may perform object caching that abstracts and stores
objects. In the case of turning to a page having the cached
objects, the page transition speed may be improved by utilizing the
cached objects and thereby omitting a process previous to the
object caching. Although there may be a difference in the page
transition speed according to contents of the document, the object
caching may improve the page transition speed, such as, for
example, by about 5 seconds if it takes 10 seconds to turn a page
without the object caching.
[0051] However, the page transition speed may not be uniform, and
may vary depending on the content of the document. Additionally,
because a user may expect that a page is turned within about 2
seconds of an associated command to turn the page, object caching
alone may not improve page transition speed sufficiently.
[0052] Among the various operations of the document viewer, it may
take the most time to generate image data of a page. Thus, in the
exemplary embodiments of the present invention, image caching may
be employed to improve the page transition speed. With image
caching, a page transition may be achieved, for example, within
about 2 seconds, regardless of the contents of the document.
[0053] That is, the document display apparatus 100 may generate and
stores image data as a page unit. The operations of generating and
storing the image data may be repetitively performed during an idle
time, such as a time during which other operations are not
performed (e.g., a page transition is not performed). Then, when
turning to a page, if it is determined that a requested page is an
image-cached page, the document display apparatus 100 may display
the image data of the stored corresponding page directly on a
screen. Thus, by using image caching, a series of operations from
parsing the document to generating the image data may be omitted
among the operations performed for outputting the document, and
this may allow the page transition speed to increase. Time taken in
turning a page may be equal to time taken in displaying the image
data on the screen, and embodiments in accordance with aspects of
the present invention may therefore, by image caching, keep a page
transition speed constant.
[0054] The controller 130 may control the image processor 110 to
generate the image data corresponding to at least one page
estimated to be turned to among a plurality of pages and store it
in the memory unit 120. In this case, the controller 130 may
control the image processor 110 to generate the image data as a
page unit.
[0055] According to an exemplary embodiment, the controller 130 may
control the image processor 110 to sequentially generate the image
data in order of neighboring the current displayed page, so that
the image data can be sequentially generated in both directions of
the previous and next pages with respect to the currently displayed
page.
[0056] According to another exemplary embodiment, the controller
130 may control the image processor 110 to sequentially generate
the image data in order of neighboring the current displayed page,
so that the image data can be sequentially generated in both
directions of the previous and next pages with respect to the
currently displayed page within a predetermined range, and the
image data can be sequentially generated in the direction of the
next page with respect to the currently displayed page beyond the
predetermined range.
[0057] If a user requests a page transition, the controller 130 may
control the image processor 110 to display the image data
corresponding to the requested page among the previously stored
image data. If the image data corresponding to the requested page
is not stored in the memory unit 120, the controller 130 may
control the image processor 110 to generate the image data
corresponding to the requested page and display it.
[0058] According to an exemplary embodiment, the controller 130 may
control the image processor 110 to generate the image data by
stepwise abstracting or excluding the individual unit elements
having a low priority, as a page transition speed increases. In
this case, the controller 130 may control the image processor 110
to give the priority to the individual unit elements according to
effects on delivering meanings of the document or based on a user's
selection. For example, in one exemplary embodiment, blocks of text
may be of lower priority than pictures, and pictures may be of
lower priority than headings. Thus, the controller 130 may control
the image processor 110 to generate the image data by abstracting
or excluding blocks of text, and, if the page transition speed
increases further, the controller 130 may control the image
processor 110 to generate the image data by abstracting or
excluding pictures, in addition to blocks of text, in accordance to
the exemplary embodiment.
[0059] Alternatively, according to another exemplary embodiment, a
user's selection may be, for example, for the image processor 110
to generate the image data by stepwise abstracting or excluding
blocks of text and abstracting or excluding headings, if pictures
have a greater effect on delivering meaning of the document,
according to the user's selection.
[0060] By giving priority to the individual unit elements according
to effects on delivering meaning of the document or based on a
user's selection, the meaning of an element, a page, or a document
may be understood even when individual elements with a low priority
are abstracted or excluded.
[0061] According to another exemplary embodiment, the controller
130 may generate the image data and a memory map for mapping a
location where the image data is stored, and then store the image
data and the memory map in the memory unit 120. In this case, when
turning to the requested page, the controller 130 may control the
image processor 110 to generate image data that excludes the
previously stored image data, by referring to the memory map.
Further, when turning to a requested page, the controller 130 may
update the memory map corresponding to the image data generated in
order of distance from the requested page.
[0062] Through a user input unit 140, a user may input his/her
selection. Specifically, the user's selection may be related to the
priority given to the individual unit elements to be shown, or a
priority of objects not to be shown in the document, based on a
page transition speed.
[0063] FIGS. 2A and 2B are exemplary embodiments of a memory
unit.
[0064] In one embodiment, the memory unit 120 may be divided into a
plurality of regions. As shown in FIG. 2A, the memory unit 120 may
include a plurality of processing regions (a first processing
region 121, a second processing region 122, a third processing
region 123, and a fourth processing region 124, for example) where
data is read and written for processing the document file, and may
also include a plurality of storing regions (a first storing region
125 and a second storing region 126, for example) where processing
results may be stored.
[0065] The first processing region 121 may be allocated to analyze
the kinds, positions, etc. of the individual unit elements within
the document. The second processing region 122 may be allocated to
abstract the analyzed individual unit elements. The third
processing region 123 may be allocated to perform a page rendering
to display one page from the abstracted individual unit elements as
an image. The fourth processing region 124 may be allocated to
generate the image data by abstracting RGB data for a screen output
from the rendering result.
[0066] Also, the first storage region 125 may store the individual
unit elements abstracted by the second processing region 122. The
second storage region 126 may store the image data generated by the
fourth processing region 124. Here, the capacity of the image
caching (the number of image data to be cached) may be increased by
increasing the memory region allocated for the second storage
region 126.
[0067] Alternatively, the memory unit 120 may include a plurality
of memories. As shown in FIG. 2B, the memory unit 120 includes a
first memory 127, a second memory 128 and a third memory 129.
[0068] The first memory 127 may process a document, that is,
perform document parsing, object caching, page rendering, image
data generation, etc.
[0069] The second memory 128 may store the individual unit elements
constituting the document. The third memory 129 may store the image
data containing the individual unit elements.
[0070] The memory unit 120 may, for example, be embodied as one or
more volatile memory storage such as SDRAM and/or non-volatile
storage such a NVRAM. Additionally, the memory unit 120 may include
a computer readable recording media such as magnetic storage media,
e.g., a hard disc, or optical recording media, e.g., DVD-RAM.
[0071] FIG. 3A shows selection items for a transition speed
function according to an exemplary embodiment of the present
invention.
[0072] Through the transition speed function according to an
exemplary embodiment, individual unit elements not processed when
generating the image data, or individual unit elements to be
deleted may be manually selected. That is, the objects not to be
processed are selected according to the kinds of the document, or
at the request of a user, and may thereby improve the page
transition speed.
[0073] The page transition speed may be associated with the number
of objects constituting the image data. Specifically, if the number
of objects in the document is decreased, it may be possible to
reduce time taken for the object caching and the page rendering. To
this end, the document display apparatus 100 may give priority to
individual objects constituting the document in an order of each
object having a lesser effect on delivering meaning, and may delete
and/or not display objects having low priority, thereby decreasing
the number of objects to be displayed. For example, in the case of
a document having a Power Point format, a master page (background
image) may not be displayed.
[0074] Further, the document display apparatus 100 may give the
priority to the individual unit elements according to a user's
selection, and may stepwise control the objects not to be displayed
in order of priority according to the selection. Specifically, the
priority may be given to the individual unit elements that belong
to a certain category (e.g., a picture, a chart, etc.), and the
number of individual unit elements to be deleted or not to be
displayed according to a user's selection may be stepwise
controlled.
[0075] Referring to FIG. 3A, an exemplary user selection menu may
include whether or not the master page is displayed (i.e., off/on)
and the number of objects not to be displayed (i.e., all delete/3N
delete/2N delete/N delete/all display) among the objects belonging
to an object category "1" are varied depending on transition speed
steps (very fast/fast/normal/slow/very slow). For example, if a
user selects "fast" among the transmission speeds, the master page
and 3N objects having low priority among the objects belonging to
the object category "1" may not be displayed to make the page
transition speed fast.
[0076] FIG. 3B is an exemplary menu screen that may be displayed
when the transition speed function of FIG. 3A is selected.
[0077] If a user selects the transition speed function in a menu
item of the document display apparatus 100, a menu screen as shown
in FIG. 3B may be displayed. In this case, a user may set up
selection items according to the transition speed on the menu
screen. Specifically, a user may set up an item of "current loading
time" corresponding to the transition speed as one of the steps
from "very fast" to "very slow." Here, whether the master page is
set to be on or off and the number of objects not to be processed
in the object category "1" may be automatically changed depending
on speed step selected.
[0078] FIG. 4A is an exemplary page order of a document.
[0079] Assuming that the document display apparatus 100 currently
displays an N page, the previous pages may be arranged in order of
an N-1 page, an N-2 page, an N-3 page, an N-4 page and an N-5 page,
and so forth, and the next pages may be arranged in order of an N+1
page, an N+2 page, an N+3 page, an N+4 page and an N+5 page, and so
forth.
[0080] The closest neighboring pages to the N page are the N+1 page
arranged next to the N page by one page, and the N-1 page arranged
previously to the N page by one page. In this case, the N+1 page
and the N-1 page are equally distant to the N page, and may
therefore be hard to distinguish in priority. Since documents are
generally read in direction of the subsequent page, exemplary
embodiments may include that the N+1 page has higher priority than
the N-1 page. Alternatively, the priority may be variously set up
according to a user's selection.
[0081] The second closest neighboring pages to the N page are the
N+2 page arranged subsequent to the N page by two pages and the N-2
page arranged previously to the N page by two pages. Thus, the
neighboring pages to the N page may be arranged in order of
priority as the N+1 page, the N-1 page, the N+2 page, the N-2 page,
the N+3 page, the N-3 page, the N+4 page, the N-4 page, the N+5
page and the N-5 page, and so forth. Alternatively, according to
another exemplary embodiment, the priority may be variously set
according to a user's selection.
[0082] FIG. 4B shows an exemplary embodiment of a memory map.
[0083] According to another exemplary embodiment of the present
invention, the document display apparatus 100 may create and store
a memory map in a storage space in which the previously generated
image data is cached.
[0084] The memory map may be used to perform mapping between the
image data and the location where the image data is stored.
Specifically, the memory map may be used to perform a mapping
between an address corresponding to a storage space and a page
number of corresponding image data stored in the storage space.
[0085] Supposing, for example, that there are eleven storage spaces
to which addresses from "0" to "10" are assigned, in an exemplary
embodiment. The document display apparatus 100, may, according to
an exemplary embodiment, generate and store eleven image data. In
this example, the generated image data may be sequentially stored
in the storage spaces to which addresses are assigned,
respectively, in order from the address of "0" to the address of
"10."
[0086] The operation of generating the image data may be performed
in an idle time, such as during when other operations are not
performed. New image data may be generated in the order according
to the storage space, up to the address of "10". In this case, the
document display apparatus 100 may delete previously stored image
data, and begin at the address of "0," and thereby store new
generated image data in the storage spaces to which the addresses
are assigned, respectively, in order from the address of "0" to the
address of "10."
[0087] As shown in FIG. 4B, in the example, the N page being
currently displayed and may be stored in the storage space to which
the address of "7" is assigned. Further, the N+1 page, the N-1
page, the N+2 page, the N-2 page, the N+3 page, the N-3 page, the
N+4 page, the N-4 page, the N+5 page and the N-5 page may be
sequentially stored in order of distance from the N page.
[0088] Specifically, the N+1 page may be stored in the storage
space to which the address of "8" is assigned, the N-1 page may be
stored in the storage space to which the address of "9" is
assigned, and the N+2 page is stored in the storage space to which
the address of "10" is assigned. In this example, the address of
"10" may be the last address of the memory map, so that the other
pages may be stored by returning to the address of "0." That is,
the N-2 page, the N+3 page, the N-3 page, the N+4 page, the N-4
page, the N+5 page and the N-5 page may be sequentially stored in
the storage spaces to which the addresses are assigned,
respectively, in order of the address of "0" to the address of
"6."
[0089] FIGS. 5A to 5C are a process of updating a memory map
according to an exemplary embodiment of the present invention.
[0090] In this embodiment, suppose that the page is turned to an
N+20 page with respect to the foregoing case shown in FIG. 4B.
[0091] According to the an exemplary embodiment, the document
display apparatus 100 sequentially generates the image data in
order of neighboring the currently displayed page, in which the
image data are generated in both directions of the previous and
next pages with respect to the currently displayed page.
[0092] When moving to the N+20 page, the document display apparatus
100 generates the page numbers to be cached with respect to the
N+20 page. Specifically, the document display apparatus 100 may
sequentially generate the page numbers in order of neighboring the
N+20 page. Referring to FIG. 5A, the pages undergo the image
caching in order of the N+20 page, the N+21 page, the N+19 page,
the N+22 page, the N+18 page, the N+23 page, the N+17 page, the
N+24 page, the N+16 page, the N+25 page and the N+15 page.
[0093] The document display apparatus 100 may compare the page
number to undergo the image caching with the page number currently
stored in the memory map shown in FIG. 4B. In this case, the
document display apparatus 100 ascertains whether there is any
duplicate page, and sets up an update flag. The update flag is set
up so as to allow the document display apparatus 100 to not
duplicate image data previously stored in the memory map.
[0094] Among the page numbers to be image-cached, an update flag of
"0" may beset for a page number being currently stored in the
memory map, and an update flag of "1" may be set for a page number
not currently stored in the memory map. In this case, the document
display apparatus 100 does not generate the pages having the update
flag of "0," but generates only the pages having the update flag of
"1."
[0095] In a comparison between the page numbers of FIG. 5A to be
image-cached and the page numbers of FIG. 4B previously stored,
there are no duplicate page numbers. Thus, as shown in FIG. 5A, the
update flag of "1" may be set so all the page numbers are to
undergo image caching.
[0096] Among the page numbers being currently stored in the memory
map, the document display apparatus 100 gives the update flag of
"0" to the page numbers equal to the page numbers to undergo the
image caching, and gives the update flag of "1" to the page numbers
different from the page numbers to undergo the image caching. The
document display apparatus 100 may delete the pages having the
update flag of "1" among the previously stored pages without
deleting the pages having the update flag of
[0097] In the example, when the page numbers to undergo the image
caching are compared with the previously stored page numbers shown
in FIG. 4B, there are no duplicate page numbers. Thus, as shown in
FIG. 5B, the update flag of "1" may be set for all the page numbers
being currently stored in the memory map. In this case, the pages
being currently stored in the memory map may all be updated.
[0098] FIG. 5C shows an exemplary memory map updated in such a
manner.
[0099] The document display apparatus 100 may sequentially update
the memory map in numerical order of the pages to be image-cached.
Specifically, the document display apparatus 100 may update the
N+20 page, to which the page is turned to, located at the address
of "7" for the N page being currently displayed, and may update the
N+21 page, the N+19 page and the N+22 page to be located at the
addresses of "8," "9," and "10," respectively, in neighboring order
of distance with respect to the address of "7" for the N+20
page.
[0100] In this case, the address of "10" is the last address of the
memory map, so that the other pages may be updated by returning to
the address of "0." That is, the N+18 page, the N+23 page, the N+17
page, the N+24 page, the N+16 page, the N+25 page and the N+15 page
may be sequentially updated in the storage spaces to which the
addresses are assigned, respectively, in order from the address of
"0" to the address of
[0101] FIGS. 6A to 6C are views for explaining a process of
updating a memory map according to another exemplary embodiment of
the present invention.
[0102] In this exemplary embodiment, the page is turned to an N+7
page with prior image data stored as in FIG. 4B.
[0103] When moving to the N+7 page, the document display apparatus
100 generates the page numbers to be cached with respect to the N+7
page. Specifically, the document display apparatus 100 may
sequentially generate the page numbers in order of distance from
the N+7 page. Referring to FIG. 6A, the pages may undergo the image
caching in order of the N+7 page, the N+8 page, the N+6 page, the
N+9 page, the N+5 page, the N+10 page, the N+4 page, the N+11 page,
the N+3 page, the N+12 page and the N+2 page, for example.
[0104] The document display apparatus 100 may compare the page
number to undergo the image caching with page numbers currently
stored in the memory map, such as shown in FIG. 4B. The document
display apparatus 100 may ascertain whether there are any pages
that are currently cached and may not need to be generated, and
thereby sets up an update flag.
[0105] In the comparison between the page numbers of FIG. 6A to be
image-cached and the page numbers of FIG. 4B previously stored,
there may be a duplicate page number. In this example, the N+5
page, the N+4 page, the N+3 page, and the N+2 page are duplicated.
As shown in FIG. 6A, the update flag of "0" is set for the N+5
page, the N+4 page, the N+3 page and the N+2 page among the page
numbers to undergo the image caching, and the update flag of "1" is
set for the other pages. Thus, among the pages shown in FIG. 6A to
undergo the image caching, the N+5 page, the N+4 page, the N+3 page
and the N+2 page are not generated as they are previously cached,
and the other pages are generated.
[0106] Meanwhile, the document display apparatus 100 may set the
update flag for the page numbers being currently stored in the
memory map.
[0107] If the page numbers to undergo the image caching are
compared with the previously stored page numbers shown in FIG. 4B,
the N+5 page, the N+4 page, the N+3 page and the N+2 page are
duplicated. Thus, as shown in FIG. 6B, the update flag of "0" is
set for the N+5 page, the N+4 page, the N+3 page and the N+2 page
as page numbers currently stored in the memory map, and the update
flag of "1" is set for the other pages. In this example, among the
page numbers being currently stored in the memory map (referring to
FIG. 6B), the N+5 page, the N+4 page, the N+3 page and the N+2 page
are not updated, but only the other pages are updated.
[0108] FIG. 6C shows the memory map updated in such a manner.
[0109] The document display apparatus 100 may sequentially update
the memory map in numerical order of the pages to be image-cached,
and may not update the pages with the update flag of "0." In this
exemplary embodiment, the document display apparatus 100 does not
newly generate the N+2 page, the N+3 page, the N+4 page, and the
N+5 page, as they are set with the update flag of "0".
Additionally, the document display apparatus may not update the
addresses of the memory map for these pages, in which the N+2 page,
the N+3 page, the N+4 page, and the N+5 page are stored. In other
words, the address of "10" storing the N+2 page, the address of "1"
storing the N+3 page, the address of "3" storing the N+4 page, and
the address of "5" storing the N+5 page may not be updated, in this
exemplary embodiment.
[0110] The document display apparatus 100 may update the N+7 page,
to which the page is turned, to be located at the address of "7"
for the N page being currently displayed, and update the N+8 page
and the N+6 page to be located at the addresses of "8" and "9,"
respectively, in neighboring order with respect to the address of
"7" for the N+7 page. In this case, the address of "10" may not be
updated, so that the previously stored N+2 page may be maintained
without change. Accordingly, the N+9 page is updated to be located,
not the address of "10", but the next available address of "0".
[0111] Meanwhile, as the address of "10" is the last address of the
memory map, the document display apparatus 100 may return to the
address of "0" and starts to update the other pages. The N+9 page
may therefore be updated to be located at the address of "0." In
this exemplary embodiment, the address of "1" is also not updated,
and thus the N+10 page is updated to be located at the address of
"2." Likewise, the N+11 page and the N+12 page are sequentially
updated to be located at the address of "4" and the address of "6,"
respectively.
[0112] FIGS. 7A to 7C are views for explaining a process of
updating a memory map according to another exemplary embodiment of
the present invention.
[0113] In this exemplary embodiment, the page is turned to an N+20
page with respect to the foregoing case shown in FIG. 4B.
[0114] According to the present exemplary embodiment, the document
display apparatus 100 may sequentially generate the image data in
order of distance from the currently displayed page, image data may
be sequentially generated in both directions of the previous and
subsequent pages with respect to the currently displayed page
within a predetermined range, and the image data may be
sequentially generated in the direction of the subsequent page with
respect to the currently displayed page beyond this predetermined
range.
[0115] Referring to FIG. 7A, an "a" part shows a case that the
image data is sequentially generated in both directions of the
previous and subsequent pages with respect to the currently
displayed page. In the case of the "a" part, the page numbers to
undergo the image caching are generated in order of the N+20 page
(currently displayed), the N+21 page, the N+19 page, the N+22 page,
and the N+18 page. On the other hand, a "b" part shows a case that
the image data is sequentially generated in the direction of only
the subsequent page with respect to the currently displayed page.
In the case of the "b" part, the page numbers to undergo the image
caching may be generated in order of the N+23 page, the N+24 page,
the N+25 page, the N+26 page, the N+27 page and the N+28 page.
Thus, according to this exemplary embodiment, the pages to undergo
the image caching may be in order of the N+20 page, the N+21 page,
the N+19 page, the N+22 page, the N+18 page, the N+23 page, the
N+24 page, the N+25 page, the N+26 page, the N+27 page and the N+28
page.
[0116] The document display apparatus 100 may compare the page
number to undergo the image caching with the page number currently
stored in the memory map, such as the memory map shown in FIG. 4B.
In this case, the document display apparatus 100 ascertains whether
there is any duplicate page, and may set an update flag. In, for
example, a comparison between the page numbers of FIG. 7A to be
image-cached and the page numbers of FIG. 4B previously stored,
there are no duplicate page numbers. Thus, as shown in FIG. 7A, the
update flag of "1" is set for all the page numbers to undergo the
image caching.
[0117] The document display apparatus 100 may give an update flag
to the page numbers being currently stored in the memory map. Page
numbers to undergo image caching may be compared with previously
stored page numbers, such as those shown in FIG. 4B, and if there
are no duplicate page number, and the update flag may be set. Thus,
for example, as shown in FIG. 7B, the update flag of "1" is set for
all the page numbers being currently stored in the memory map. In
this case, the pages being currently stored in the memory map may
all be updated.
[0118] FIG. 7C shows the memory map updated in such a manner.
[0119] The document display apparatus 100 may sequentially update
the memory map in numerical order of the pages to be image-cached.
Specifically, the document display apparatus 100 may update the
N+20 page, to which the page is turned, to be located at the
address of "7" for the N page being currently displayed, and
updates the N+21 page, the N+19 page and the N+22 page to be
located at the addresses of "8," "9," and "10," respectively, in
neighboring order with respect to the address of "7" for the N+20
page.
[0120] In this exemplary embodiment, as the address of "10" is the
last address of the memory map, the other pages may be updated by
returning to the address of "0." That is, the N+18 page, the N+23
page, the N+24 page, the N+25 page, the N+26 page, the N+27 page
and the N+28 page may be sequentially updated in the storage spaces
to which the addresses are assigned, respectively, in order from
the address of "0" to the address of "6."
[0121] Exemplary embodiments of the present invention provide an
apparatus and method for displaying a document, in which a page
transition speed may be maintained regardless of contents of the
document and a page may be turned within an acceptable period, such
as with two seconds, for example.
[0122] Also, factors associated with the performance of a document
viewer may be manually configured to improve the performance of the
document viewer. Further, exemplary embodiments may provide a user
interface to configure a page turning speed that a user finds
acceptable.
[0123] Aspects of embodiments of the present invention may be
embodied as computer programs and implemented on tangible computer
readable recording medium. Examples of computer readable recording
medium may include volatile, nonvolatile, magnetic, and optical
storage media (e.g., EEPROM, ROM, RAM, floppy disc, hard disc,
FLASH, CD-ROM, and DVD).
[0124] Although exemplary embodiments of the present invention have
been shown and described, it will be appreciated by those skilled
in the art that changes may be made in these embodiments without
departing from the principles and spirit of the invention, the
scope of which is defined in the appended claims and their
equivalents. Additionally, expressions such as "at least one of",
when preceding a list of elements, modify the entire list of
elements and do not modify each element of the list.
* * * * *