United States Patent [19J
`Yanker
`
`I lllll llllllll Ill lllll lllll lllll lllll lllll lllll lllll lllll llllll Ill lllll llll
`US005187776A
`5,187,776
`[11) Patent Number:
`[45) Date of Patent:
`Feb. 16, 1993
`
`[54)
`
`IMAGE EDITOR ZOOM FUNCTION
`
`[75)
`
`Inventor: Peter C. Yanker, Portola Valley,
`Calif.
`
`[73) Assignee:
`
`International Business Machines
`Corp., Armonk, N.Y.
`
`[21) Appl. No.: 367,159
`
`[22) Filed:
`
`Jun. 16, 1989
`
`Int. Cl.5 .......................... G06F 3/14; G09G 5/34
`[51)
`[52) U.S. Cl ..................................... 395/157; 395/161;
`395/139; 340/724; 340/726; 340/721
`[58) Field of Search ................ 364/521, 518; 340/721,
`340/731, 726, 724; 382/47; 395/157, 161, 155,
`139, 147, 146
`
`[56)
`
`References Cited
`U.S. PATENT DOCUMENTS
`Re. 31,200 4/1983 Sukonick et al. ................... 340/724
`4,148,073 4/1979 Slobodzian .......................... 358/240
`4,503,427 3/1985 Iida ...................................... 340/731
`4,528,642 7 /1985 Waller ................................. 364/900
`4,532,605 7/1985 Waller ................................. 364/900
`4,533,910 8/1985 Sukonick et al. ................... 340/721
`4,546,349 10/1985 Prohofsky et al. ................. 340/731
`4,694,345 9/1987 Rodgers .............................. 358/216
`4,720,703 1/1988 Schnarel, Jr. et al. ............. 340/709
`4,734,690 3/1988 Waller ................................. 340/729
`
`4,751,507 6/1988 Hama et al. ......................... 340/724
`4,785,296 11/1988 Tabata et al. ....................... 340/731
`4,800,379 1/1989 Yeomans ............................. 340/731
`4,821,031 4/1989 Roberts ............................... 340/731
`
`OTHER PUBLICATIONS
`PC Storyboard, International Business Machines Cor(cid:173)
`poration, First Edition, Mar. 1985, pp. 85-88.
`Microsoft Windows Paint User's Guide (Version 2.0),
`1987, pp. (3-31)-(3-34).
`Primary Examiner-Heather R. Herndon
`Assistant Examiner-Raymond J. Bayerl
`Attorney, Agent, or Firm-Perman & Green
`[57)
`ABSTRACT
`An Image Editor includes a ZOOM function wherein
`other Image Editor actions are invokable and operable
`in whatever zoom level is currently in effect. The zoom
`mode is a state of the Image Editor in that invoked
`actions are performed in a normal lX pel size image but
`are displayed to an operator in an enlarged, flat pel,
`zoom equivalent. Whe the ZOOM function is invoked a
`displayed zoom window is automatically centered upon
`a present position of a cursor as is also a selectively
`displayable viewport, the viewport showing the relative
`position of the cursor within the lX image.
`
`1 Claim, 3 Drawing Sheets
`
`10
`
`14
`
`12
`
`GOOGLE Ex. 1042
`Google v. Philips
`
`

`
`U.S. Patent
`
`Feb. 16, 1993
`
`Sheet 1 of 3
`
`5,187,776
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`10
`
`DISPLAY
`MEMORY
`
`3
`
`5
`
`MASS
`STORE
`
`CPU
`
`4
`
`2 MEMORY
`TEXT BUFFER
`PASTE BUFFER
`WORLD PLANE
`BUFFER
`,......_,_7
`Fl G. 1
`MOUSE
`
`6
`
`10
`
`14
`
`12
`
`FIG. 2
`
`GOOGLE Ex. 1042
`Google v. Philips
`
`

`
`U.S. Patent
`
`Feb. 16, 1993
`
`Sheet 2 of 3
`
`5,187,776
`
`10
`
`12
`
`FIG. 3
`
`GOOGLE Ex. 1042
`Google v. Philips
`
`

`
`U.S. Patent
`
`Feb. 16, 1993
`
`Sheet 3 of 3
`
`5,187,776
`
`20
`
`ESTABLISH 1 X
`IMAGE IN MEMORY 4
`
`DETERMINE CURSOR 16
`POSITION IN WORLD
`PLANE COORDINATES
`
`DETERMINE, BASED ON
`ZOOM LEVEL, PEL SIZE
`
`DETERMINE, USING
`CURSOR 16 COORDINATES,
`COORDINATES OF
`ZOOM WINDOW
`
`DETERMINE VIEWPORT
`12 COORDINATES
`
`MAGNIFY PELS AND
`DISPLAY ZOOM WINDOW
`COPY VIEWPORT 12
`TO DISPLAY
`
`INTERACT ~TH
`USER VIA KEYSTROKES
`
`FIG. 4
`
`22
`
`24
`
`26
`
`28
`
`30
`
`32
`
`34
`
`GOOGLE Ex. 1042
`Google v. Philips
`
`

`
`1
`
`IMAGE EDITOR ZOOM FUNCTION
`
`5,187,776
`
`2
`unmagnified image, the indicator position being located
`substantially at a center of the second window. The
`second window is displayed or is not displayed depend(cid:173)
`ing upon input from the user.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`The above set forth and other features of the inven(cid:173)
`tion will be made more apparent in the ensuing Detailed
`Description of the Invention when read in conjunction
`10 with the attached Drawings, wherein:
`FIG. 1 is a block diagram of an information process(cid:173)
`ing system embodying the invention;
`FIG. 2 shows in detail the organization of the display
`screen of FIG. l;
`FIG. 3 illustrates the display screen and shows a
`magnified portion of an image and a viewport showing
`an unmagnified portion of the image, both the screen
`and viewport having an associated cursor; and
`FIG. 4 is a flow chart that illustrates a method of
`20 initializing the zoom function of the invention.
`DETAILED DESCRIPTION OF A PREFERRED
`EMBODIMENT OF THE INVENTION
`The following description of the invention is made in
`the context of an audio/visual application processor
`implemented on an IBM TM PS/2 TM computer system
`(IBM and PS/2 are trademarks of the IBM Corporation
`of Armonk, N.Y.). It should be realized though that the
`teaching of the invention may be practiced with a num(cid:173)
`ber of different types of information processing systems
`in support of a number of different types of application
`programs that provide a visual display.
`Referring first to FIG. 1 in conjunction with FIG. 2
`there is shown a visual display screen 10. Associated
`with display screen 10 is a read/write display memory 1
`wherein stored data is read out and displayed on the
`screen 10 in a conventional manner. An individual or a
`group of storage locations within the display memory 1
`corresponds to individual pixels or pels of the display
`screen 10. The display memory 1 is coupled to a central
`processing unit (CPU) 2, the CPU 2 further being cou(cid:173)
`pled via a bus 3 to a main memory 4 wherein instruc(cid:173)
`tions are loaded and stored from a mass storage device
`S. Certain of the stored instructions control the CPU 2
`to perform an Image Editor function, including the
`image Zoom or enlargement function of the invention.
`Other functions associated with the Image Editor in(cid:173)
`clude, by example, Text, Line, Sketch, Cut, Paste, Box,
`and Fill functions. As will be made apparent these other
`functions may be invoked and executed concurrently
`with the Zoom function. The other functions operate
`upon an unmagnified, IX copy of the image stored
`within a World Plane (WP) image buffer in memory 4.
`The enlarged portion of the image that is stored within
`display memory 1 and displayed by screen 10 is a win-
`dow or viewport, initially centered upon an image cur(cid:173)
`sor, into the IX WP image. The enlarged portion of the
`WP image is displayed with a logical pel size that is a
`function of the zoom magnification level in effect. An
`enlarged logical pel is comprised of some number of
`physical screen pels or pixels.
`A data entry device such as a keyboard 6 and a mouse
`7 enables a user of the system to interact with the Image
`Editor in a manner to be described to create, modify
`and store graphical images. Textual data entered is also
`temporarily stored in a Text Buffer (TB) within mem(cid:173)
`ory 4. The data stored within the display memory 1 may
`
`FIELD OF THE INVENTION
`This invention relates generally to visual display 5
`methodology and, in particular, to a method of display(cid:173)
`ing with a zoom function a magnified portion of an
`image.
`
`BACKGROUND OF THE INVENTION
`In a publication entitled "Using PC Storyboard",
`Information Update SN60-1796, November 1985, pub(cid:173)
`lished by the IBM Corporation, Armonk, N.Y., there is
`described at pages 85-88 the functionality of a zoom, or
`image magnification, function for an applications pro- 15
`gram entitled "PC Storyboard". While providing for
`individual pel, or pixel, enlargement this prior art zoom
`function does not center the the zoom function at the
`cursor position upon the display screen. This prior art
`zoom function also does not scroll a zoom viewport that
`displays an unmagnified view of the zoomed image
`portion.
`It is thus an object of the invention to provide a zoom
`function that centers the magnified portion of a visual
`image upon a display cursor.
`It is another object of the invention to provide a
`zoom function having a viewport that scrolls through
`an image as a cursor is moved.
`
`25
`
`30
`
`SUMMARY OF THE INVENTION
`The foregoing problems are overcome and the ob(cid:173)
`jects of the invention are realized by a method of oper(cid:173)
`ating an Image Editor having a zoom function wherein
`other Image Editor actions are invokable and operable
`in whatever zoom level is currently in effect. The zoom 35
`mode is a state of the Image Editor in that invoked
`actions are performed in a normal IX pel size image but
`are displayed to an operator in an enlarged, fat pel,
`zoom equivalent. When the ZOOM function is invoked
`a displayed zoom window is automatically centered 40
`upon a present position of an indicator, or cursor, as is
`also a selectively displayable viewport for showing the
`relative position of the cursor within the IX image.
`A method of the invention of operating an Image
`Editor in response to input from a user includes the 45
`steps of entering a zoom mode of operation wherein a
`displayed image is magnified and storing in a memory
`an unmagnified copy of the image. The method further
`includes the steps of, responsive to an indicator posi(cid:173)
`tioned by the user within the displayed image, determin- 50
`ing the indicator position in coordinates associated with
`the unmagnified image, determining a magnification
`level currently in effect and determining a required
`display size of a display screen pel magnified to the
`current magnification level. Responsive to the deter- 55
`mined indicator position and to a predetermined maxi(cid:173)
`mum display size the method includes a step of deter(cid:173)
`mining coordinates, relative to the unmagnified image,
`of a first window defining a portion of the image to be
`displayed as a magnified image. The first window coor- 60
`dinates are determined such that the indicator position
`is located substantially at a center of the first window.
`An additional step of displaying the magnified portion
`of the image within the first window is accomplished,
`the magnified portion being displayed with the magni- 65
`fled pel size. The method also determines coordinates
`within the unmagnified image of a second window for
`defining a portion of the image to be displayed as an
`
`GOOGLE Ex. 1042
`Google v. Philips
`
`

`
`5,187,776
`
`3
`provide information for displaying a monotone or a
`color image, depending upon the characteristics of the
`particular system display screen 10. In a preferred em(cid:173)
`bodiment of the invention the display screen 10 displays
`color images.
`The ZOOM function of the invention provides seven
`user selectable levels (IX, 2X, 4X, 8X, 16X, 32X and
`64X) of image enlargement. A specific zoom level stays
`in effect until changed in magnification by another
`ZOOM function or until deactivated. In accordance 10
`with one aspect of the invention other Image Editor
`functions are usable within any of the zoom levels.
`A ZOOM VIEWPOR T function is controlled by a
`user to switch between displaying a zoom viewport 12
`and not displaying the zoom viewport 12. The zoom 15
`viewport 12 is a relatively small window within the
`zoomed display 10 that displays iri "normal" size (IX)
`an area surrounding a cursor 14. An enlarged, fat pel,
`cursor 16 within the zoomed image corresponds to the
`cursor 14. The zoom viewport 12 is only displayed 20
`when zooming is in effect, that is for image enlarge(cid:173)
`ments greater than IX and when specifically enabled by
`the ZOOM VIEWPOR T function.
`Upon selection by a user the display screen 10 dis(cid:173)
`plays the image 18 enlarged in accordance with the 25
`particular zoom level in effect. The zoomed area is
`centered around the cursor 14. The zoom level remains
`in effect until either changed by a later ZOOM function
`or until deactivated by an ESC code entered while in an
`idle state. The entry of the ESC code restores the nor- 30
`ma! display (zoom level IX).
`In accordance with the invention all Image Editor
`actions are invokable and operable in whatever zoom
`level is in effect. By example, CUT and PASTE func(cid:173)
`tions operate at all zoom levels. Further in accordance 35
`with this aspect of the invention alphanumeric text may
`be entered with the TEXT function, an image may be
`saved to disk or drawing can be accomplished while the
`ZOOM function is invoked. That is, the zoom mode
`becomes a state of the Image Editor in that invoked 40
`actions are performed upon the unmagnified copy of the
`image within the WP buffer with a normal IX pel size
`but are displayed to the operator in an enlarged, fat pel,
`equivalent. For example, when entering text while in
`zoom mode the text is written to the IX TB in a normal, 45
`unmagnified, size as determined by the font and point
`size in use independently of the zoom level in effect.
`However, text occurring within the zoom window is
`displayed enlarged to the current zoom level. Upon a
`return to normal view (IX) the text appears in the 50
`proper size for the standard IX screen display. When
`entering text with a large zoom lctvel in effect, such as
`64x, the text field may not fit within the screen display.
`The invention provides for automatically panning the
`display as needed to keep up with the cursor 16 position. 55
`By example, one Image Editor function is known as
`FILL. If required by a particular image the FILL func(cid:173)
`tion also fills image areas outside of the currently dis(cid:173)
`played zoom window. Thus, the operation of the FILL
`function proceeds in a normal (IX) fashion regardless of 60
`the zoom level currently in effect. Similarly a PASTE
`function pastes down a full paste buffer (PB) area, dis(cid:173)
`played in a properly enlarged format, even though the
`PB extends beyond the boundaries of the enlarged dis(cid:173)
`play. It is noted that write to disk functions such as 65
`SA VE and SA VE AND EXIT write the IX version of
`the current image to disk even when the ZOOM func(cid:173)
`tion is displaying an enlarged view of the image. If
`
`4
`desired the enlarged view may be saved to disk using a
`RESIZE function to generate the enlarged view. The
`RESIZE function generates an enlarged view of an
`image at a normal, physical, pel size that becomes a new
`IX image. The new IX image is then stored using
`SAVE.
`If the ZOOM VIEWPORT function is enabled the
`zoom viewport 12 is generated and displayed at a cor(cid:173)
`ner of the display 10 whenever a zoom level other than
`IX is in effect. The zoom viewport 12 displays in IX
`magnification a portion of the image surrounding the
`cursor 14 location. The zoom viewport 12 thus provides
`a perspective of the location of cursor 16 within the IX
`WP image. The presence of the zoqm viewport 14 also
`indicates to a user that a ZOOM function is in effect.
`Upon selection by the operator the ZOOM VIEW(cid:173)
`POR T function determines either whether the viewport
`12 is displayed (ON) during zoom mode or whether it is
`not displayed (OFF). The option selected remains in
`effect until changed to the opposite state by another
`ZOOM VIEWPOR T function.
`As the operator repositions the cursor 16 within the
`magnified image window the cursor 14 moves to reflect
`the cursor 16 position within the IX WP image copy.
`As cursor 16 is panned across the enlarged image the
`cursor 14 of the viewport 12 moves relative to the
`image area approximately in unison. The portion of the
`IX image contained within viewport 12 changes only
`when the cursor 14 intersects an edge of the viewport
`12. This condition is detected and the coordinates of an
`adjacent portion of the unmagnified IX image from the
`WP buffer are determined and the image displayed. The
`adjacent portion is sized as a function of the size of the
`viewport window 12 and the position of the cursor 14.
`The newly displayed portion of the IX image has the
`cursor 14 positioned at the edge of the viewport where
`it entered, that is opposite the edge that it initially inter(cid:173)
`sected. By example, if cursor 16 movement causes the
`cursor 14 to intersect, in WP coordinates, the left edge
`of the viewport 12 of FIG. 3 CPU 2 detects this condi(cid:173)
`tion, accesses the IX image copy and displays the adja(cid:173)
`cent image portion in viewport 12. In the newly dis(cid:173)
`played portion the cursor 14 is positioned adjacent to
`the right edge of the viewport 12. Thus the viewport 12
`"pans" in increments of viewport 12 dimensions rather
`than moving continuously as the cursor 16 and the
`enlarged view in the zoom window does.
`Also, if the cursor 16 intersects an edge of the view(cid:173)
`port 12 the viewport 12 is shifted to another position
`upon the display 10. This feature of the invention ena(cid:173)
`bles the zoom area previously under or behind the view(cid:173)
`port 12 to be displayed and accessed.
`It should be noted that the style of cursor in viewport
`12 is the same as the style of cursor specified for use in
`the Image Editor. At any time while in zoom mode a
`change in cursor style also changes the style of cursor
`14. By example, the cursor 14 may have the shape of a
`cross, a dot or may be invisible.
`While in zoom mode the cursor 16 is a square shaped
`group of visually distinct pels having a transparent cen(cid:173)
`ter region. When the cursor 16 reaches an edge of the
`display 10 any further attempted cursor movement in
`the same direction causes the screen 10 to pan in order
`to accommodate the continuing movement of the cur(cid:173)
`sor 16. Such panning and cursor movement stops when
`an actual edge of the WP image within memory 2 is
`reached. By example, when cursoring left and upon
`reaching the edge of the current display 10 further
`
`GOOGLE Ex. 1042
`Google v. Philips
`
`

`
`25
`
`5
`cursoring left continues, assuming the image edge is not
`yet reached, and the screen view pans in unison to keep
`up with the location of the cursor. In this case image
`pels on the right edge of the display are pushed off to
`the right as new pels push on from the left edge to show
`the newly displayed portion of the image. The WP
`image is similarly accessed and displayed for cursor 16
`movement that occurs when moving right, up or down.
`During the display of enlarged zoom views of an
`image the cursor 16 moves in increments appropriate 10
`for the zoom level. For example, when at a magnifica(cid:173)
`tion level of 64X, movement typically occurs in incre(cid:173)
`ments of a single, enlarged pel. In this regard it is noted
`that at magnifications above IX that the cursor 16 is
`moving in "logical" pels and not in "physical" pels. By 15
`example, if zoom level 64X is selected the display 10
`still has a physical resolution of some number of pels,
`such as 640X480. However, from a logical point of
`view the image has been enlarged such that only a few
`"logical" pels of the image are displayed on the screen 20
`10. Each pel is physically sized along both x and y
`screen coordinates by the CPU 2 such that it encom(cid:173)
`passes a plurality of pels for display purposes, but each
`enlarged "fat" pel represents but a single logical pel of
`the image. From a ZOOM function perspective cursor
`16 movement, and the physical size of the cursor 16,
`corresponds to the logical pel size.
`Predetermined cursor direction keys of the keyboard
`6 move the cursor 16 accordingly - left, right, up, down, 30
`and in the four diagonal directions. CTRL versions of
`these keys, that is depressing the CONTROL key simul(cid:173)
`taneously with a cursor direction key, moves the cursor
`16 directly to the WP image edges, as is done for nor(cid:173)
`mal, non-zoom, cursoring. SHIFT versions of these 35
`keys move the cursor 16 in one pel increments, again as
`for normal cursoring.
`In accordance with a further aspect of the invention
`there a•e provided other cursoring conventions when
`operating in the zoom mode. ALT versions of predeter- 40
`mined keyboard. keys, preferably the numeric keypad
`cursor keys, move the cursor 16 directly to the edges of
`the currently displayed image, thereby keeping cursor
`16 movement restricted to within the current display.
`ALT S positions the cursor 16 to the center of the cur- 45
`rently displayed image in a manner somewhat analo(cid:173)
`gous to CTRL S that moves the cursor to the center of
`the WP image.
`Further in accordance with this aspect of the inven(cid:173)
`tion there is provided another special cursoring conven- 50
`tion that is enabled by, in this embodiment of the inven(cid:173)
`tion, the CTRL Z key. When depressed this keystroke
`combination causes the CPU 2 to record the current
`cursor 16 screen coordinate position and thereafter
`center the cursor 16 and the surrounding enlarged por- 55
`ti on of the image at the middle of the display screen 10.
`The effect of this keystroke combination is to center an
`enlarged view of the image around a current location of
`the cursor 16. If not in zoom mode when this keystroke
`combination is entered CPU 2 instead invokes the zoom 60
`mode and establishes the display screen 10 accordingly,
`using the zoom level last selected during a previous
`zoom mode operation.
`If the zoom viewport 12 is enabled during the direct
`cursoring accomplished in conjunction with the ALT, 65
`SHIFT and CTRL keys the zoom viewport 12 is up(cid:173)
`dated in unison with whatever changes occur in the
`cursor 16 location and screen display.
`
`5,187,776
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`6
`Depressing another predetermined key, in this case
`ESC, terminates the zoom mode if no other Image Edi(cid:173)
`tor functions are also invoked. Terminating the ZOOM
`function causes the screen 10 to display a normal IX
`image. By example, if drawing a box while in zoom
`mode, pressing ESC while in the midst of sizing an
`elastic box outline causes an escape from the BOX func(cid:173)
`tion back to an Image Editor idle state. A zoom level
`presently in effect, such as 32X, continues. If the BOX
`action is instead terminated normally, subsequentially
`pressing ESC terminates the ZOOM function. Termina(cid:173)
`tion of the ZOOM function causes CPU 2 to save the
`current zoom state including the current zoom level, for
`example 32X, and whether the zoom viewport is on or
`off. When the ZOOM function is again invoked the
`saved parameters are retrieved and used to initially
`establish the zoom processor state. Termination of the
`zoom function also releases the WP buffer area.
`Referring to FIG. 4 there is shown in block diagram
`form the initialization of the ZOOM function. At block
`20 CPU 2 recognizes a CTRL Z keystroke from key(cid:173)
`board 6 and invokes the ZOOM function. At block 22
`the IX WP image is established in the WP buffer. In this
`regard it is noted that if a IX image already exists the
`image is copied from display memory 1 into the WP
`buffer. At block 24 the position of the user positioned
`cursor is determined within the image, the cursor posi(cid:173)
`tion being referenced to the coordinates of the WP
`image. At block 26 a current zoom level is determined
`and the corresponding expanded logical pel size is cal(cid:173)
`culated. The initial zoom level is set to the level in effect
`when the ZOOM function was last terminated. At block
`28 the coordinates of the zoom window are determined,
`that is, what portion of the copy of the IX image in the
`WP buffer will be displayed in an enlarged format
`within the zoom window. The coordinates of the zoom
`window are a function of the cursor position, in that the
`window is centered on the cursor, the zoom level and
`the size of the zoom window. Next, at block 30, the
`coordinates of the viewport 12 are determined. The
`viewport 12 is nominally defined to have an area equal
`to approximately one sixteenth of the zoom display
`window. The zoom display window normally occupies
`substantially the entire available area of the display
`screen 10. At block 32 the CPU 2 accesses those IX pels
`within the WP buffer that lie within the calculated
`coordinates of the zoom window. The accessed pels are
`expanded in accordance with the calculated logical pel
`size and are written to the display memory l, thereby
`creating the expanded image. Also, the IX pels from the
`WP buffer are copied to the display memory 1 such that
`the viewport 12 appears in a corner of the zoom win(cid:173)
`dow. Thereafter, the CPU 2 interacts with a user via the
`keyboard 6 and/or mouse 7 to pan through the image
`and to invoke other of the image editor functions.
`In accordance with another aspect of the invention
`the zoom level may be changed while the ZOOM func(cid:173)
`tion is invoked. An operator changes the magnification
`level via the keyboard 6 and the CPU 2 recalculates the
`logical pel size and the zoom window coordinates. The
`zoom window coordinates are a function of the present
`position of the cursor within the IX image in that the
`cursor is by definition taken to be the center of the
`window. That is, blocks 24-34 of the flowchart of FIG.
`4 are executed. While the invention has been particu(cid:173)
`larly shown and described with respect to a preferred
`embodiment thereof, it will be understood by those
`skilled in the art that changes in form and details may be
`
`GOOGLE Ex. 1042
`Google v. Philips
`
`

`
`5,187,776
`
`7
`made therein without departing from the scope and
`spirit of the invention.
`Having thus described my invention, what I claim as
`new, and desire to secure by Letters Patent is:
`1. In a system having image display means comprising
`a plurality of physical pels, a method of operating an
`image editor in response to input from a user of the
`system, the method comprising the steps of:
`displaying a magnified portion of a first image as a
`second image comprised of a plurality of logical 10
`pels having a size that is a function of a magnifica(cid:173)
`tion level in effect, the second image having a first
`cursor positioned therein;
`displaying within the second image a viewport con(cid:173)
`taining a portion of the first image, the portion 15
`corresponding to the magnified portion, the view(cid:173)
`port having a vertical and a horizontal dimension
`corresponding to a plurality of physical pels of the
`
`8
`first image and further having a second cursor
`having a position that corresponds to the position
`of the first cursor;
`responsive to the user repositioning the first cursor
`such that the first cursor would be located outside
`of the displayed second image,
`shifting the second image in increments of logical pels
`in unison with movement of the first cursor; and
`responsive to the second cursor reaching a first edge
`of the viewport in response to the movement of the
`first cursor,
`shifting the viewport by a plurality of physical pels
`that correspond to the vertical or the horizontal
`dimension of the viewpo·rt such that the second
`cursor is positioned substantially adjacent to a sec(cid:173)
`ond edge of the viewport that is oppositely dis(cid:173)
`posed to the first edge.
`• • • • •
`
`20
`
`25
`
`30
`
`35
`
`40
`
`45
`
`50
`
`55
`
`60
`
`65
`
`GOOGLE Ex. 1042
`Google v. Philips