Abstract:
A system, a method and an article of manufacture for uncentering an image of a video stream on a video display is provided. The image of the video stream is displayed uncentered on a video display at a position that depends on the aspect ratio of the video stream and the aspect ratio of the display used to view the video stream. Once uncentered, the image of the video stream is not shifted for the duration of the video session unless a user provides input to change the position. Various positions of the image of a video stream are available to accommodate user preferences or to prolong the life of the video display.

Description:
TECHNICAL FIELD 
     This invention relates to displaying video streams and methods related thereto. In particular, the invention relates to determining the aspect ratio of the video display and the video stream and shifting the location of the image of the video stream on the display to maximize the life of the display or to avoid known defects in the display. 
     BACKGROUND 
     With the advent of widescreen displays in which the display screen has an aspect ratio of 16:9 and a plurality of video-stream aspect ratios, there are often black bands typically above and below the displayed image of the video stream or alternately to the left and right of the displayed image of the video stream. For example, when viewing a video stream with a larger aspect ratio than the display it is being viewed on, these black bands appear above and below the centered image of the video stream to produce what is informally known as a letterbox image. When viewing a video stream with a smaller aspect ratio than the display it is being viewed on, these black bands appear to the left and the right of the centered image of the video stream. In those cases where the video stream and the display have the same aspect ratio, no black bands occur. 
     This current method of centering the displayed image of the video stream when the aspect ratio of the video stream and the display are different can lead to uneven aging of pixels and possible pixel burnout on cathode ray tube (CRT) high definition televisions (HDTVs) and plasma screens. The uneven aging of pixels is observable as burned-in images of the bars bracketing the letterbox image and additional burn in effects in the area where the image is displayed. The bars may eventually “burn” into the screen, becoming visible when an image of a different aspect ratio is viewed. CRT screens and plasma screens are both susceptible to burn-in. Conversion circuitry that is capable of expanding a displayed image both horizontally and vertically may be used to eliminate the black bands. The conversion circuitry typically alters the image&#39;s aspect ratio to match that of the screen to eliminate the bars; however, this will result in distorted unnatural looking images. Therefore there is a need to improve the displaying of images with aspect ratios that are different than the aspect ratio of the display component. 
     SUMMARY OF THE INVENTION 
     The present invention provides a system, a method and an article of manufacture for uncentering an image of a video stream on a video display. The image of the video stream is displayed uncentered on a video display at a position that depends on the aspect ratio of the video stream and the aspect ratio of the display used to view the video stream. Once uncentered, the image of the video stream is not shifted for the duration of the video session unless a user provides input to change the position. Various positions of the image of a video stream are available to accommodate user preferences or to prolong the life of the video display. Synonyms for display are screen and display screen. A synonym for video stream is images. 
     In method form, exemplary embodiments include a method for displaying an image of a video stream on a display, comprising: obtaining an aspect ratio of the display; obtaining an aspect ratio of the video stream; determining whether the aspect ratio of the display is different than the aspect ratio of the video stream; and responsive to determining that the aspect ratio of the display is different than the aspect ratio of the video stream, positioning the image of the video stream on the display to uncenter the image on the display. Additional exemplary method embodiments include selecting a random position of the image on the display at a selected interval and displaying the image on the display at the random position. 
     In system embodiments the present invention provides display system, comprising: a display for displaying an image of a video stream and a player coupled to the display. The player further comprising: a display buffer for buffering and processing the video stream and providing the video stream to the display; a processor for controling the display buffer, wherein the processor is configured to: obtain an aspect ratio of the display; obtain an aspect ratio of the video stream; determine whether the aspect ratio of the display is different than the aspect ratio of the video stream; and responsive to determining that the aspect ratio of the display is different than the aspect ratio of the video stream, positioning the image of the video stream on the display to uncenter the image on the display. 
     For a fuller understanding of the nature and advantages of the present invention, reference should be made to the following detailed description taken together with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Referring now to the drawings in which like reference numbers represent corresponding parts throughout: 
         FIG. 1  shows a view of a representative video display system; 
         FIG. 2  shows examples of currently implemented video image aspect ratios for common screen and television/motion picture display aspect ratios; 
         FIG. 3  shows an overview of the volume space on a DVD video disk; 
         FIG. 4  shows the breakdown of the contents of the DVD-Video zone, to include the control data; 
         FIG. 5  shows the breakdown of the contents of the control data, to include the aspect ratio of the video stream; 
         FIG. 6  shows a flowchart of a process to display an image of the video stream consistent with the aspect ratio of the video stream and the aspect ratio of the display; 
         FIG. 7  shows a flowchart of a process to shift the display of an image of the video stream vertically; 
         FIG. 8  shows a flowchart of a process to shift the display of an image of the video stream horizontally; 
         FIG. 9  shows a flowchart of a process to use a remote control input for the present invention; and 
         FIG. 10  illustrates the display of an image of the video stream that is uncentered and repositioned to the top of the display. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     Referring first to  FIG. 1 , an example of a display system  100  that may be used to implement the present invention is shown. Display system  100  may comprise display  130 , player  101  coupled to display  130  and remote control  140 . Player  101  provides a source of video data and may comprise a DVD (digital video disk), VHS (video home system) tape player playing a VHS tape, a satellite video receiver, CD (compact disk) Video, etc., as are commercially available. For example, DVD player Model # DVP-NS575P/S manufactured by the Sony Corporation may be used for player  101 . Display  130  may be a television (TV), a computer CRT display, a plasma display, a projection TV, or any other display for displaying video information. Remote control  140  may be a remote control for display system  100  that uses wireless, direct wire connection, optical communication, etc., for communication with display system  100 . 
     In one embodiment ( FIG. 1 ) of player  101 , encoded video data is read from disk  110  by laser  120 . Laser  120  may comprise any laser for reading and or writing optical information. For example laser  120  may comprise a laser producing a wavelength of light spanning beyond the visible spectrum (i.e. infrared to ultraviolet) for use with DVD video disks or other optical disks. Error Correction Code (ECC)  121  is first applied to the encoded video data (information on ECC may be found in U.S. Pat. Nos. 4,358,848 and 3,755,779) to produce corrected video data with minimum errors. After ECC processing, the corrected video data may be stored in track buffer  122  before it is decoded by video decoder  123 . Video decoder  123  is typically an MPEG (Moving Picture Experts Group) decoder, such as MPEG-1 (ISO/IEC 11172), MPEG-2 (ISO/IEC 13818), or MPEG-4 (ISO/IEC 14496). A typical MPEG-2 video decoder is the Vaddis5R, chip number ZR36750, manufactured by the Zoran Corporation. 
     Track buffer  122  is used to compensate for disk access discontinuities such as when laser  120  jumps from one layer to another in a dual-layer DVD video disk. Video decoder  123  processes corrected video data to produce a video stream suitable for display on display  130 . In the preferred embodiment a DVD video disk may supply the video data to video decoder  123 . Video decoder  123  processes the video data to produce a video stream. The video stream is transmitted to display buffer  124 , where additional processing may occur. For example, the corrected video data may be processed to produce horizontal or vertical shifting of the video picture displayed on display  130 . After the additional processing, the image of the video stream is displayed on display  130 . Display  130  is typically connected to player  101  via electrical cabling. However, display  130  may be connected via optical cabling or may be wirelessly connected. Alternatively, a VHS tape may supply the video data to video decoder  123 . Video decoder  123  processes the video data from any source (i.e. VHS, DVD, etc.) to produce a video stream. 
     Processor  125  controls display buffer  124  to control the buffering and processing of the video stream by display buffer  124 . After buffering and processing the video stream, display buffer  124  provides the video stream to display  130 . Additionally, processor  125  receives input from remote  140  via remote uplink  126 . Remote uplink  126  is coupled to processor  125  and receives information from remote control  140  responsive to user input at remote control  140 . 
     Processor  125  receives input from track buffer  122  regarding the control data of the video title set information  321 , (see  FIG. 4-5 ). Control data of the video title set information  321 , contains critical logistical information needed by player  101 , such as the video compression mode  421 , which may designate MPEG 1, 2, or 4. Video compression mode  421  is needed by video decoder  123  to properly decode the video stream. For example, an MPEG-4 encoded video stream needs an MPEG-4 decoder. Processor  125  provides the video compression mode  421  to video decoder  123 , for proper decoding of the encoded video stream. 
     Display  130  has information bearing medium  199  which stores the aspect ratio of display  130 . This information bearing medium is typically a semiconductor chip. This information bearing medium can be queried by processor  125 , so that processor  125  may obtain the aspect ratio of the video stream and the aspect ratio of the display. Alternately, processor  125  can access display library  198  which has the aspect ratios of known displays stored for recall. The user may access this library via remote  140  and toggle until the correct aspect ratio for display  130  is shown. Therefore the user is able to input the aspect ratio of display  130  via library  198  using remote  140 . 
       FIG. 1  illustrates a typical method of displaying the letterbox video format, by centering image  131  between two horizontal black bands  132  on display  130 . As described previously this may result in uneven aging of pixels and pixel burnout on CRT and plasma screens, which may be observable as burned-in images of the bars bracketing the letterbox. 
       FIG. 2  shows display screens  200 ,  210 , and  220  with an aspect ratio of 4:3. Also shown in  FIG. 2  are display screens  230 ,  240 , and  250  with an aspect ratio of 16:9. In  FIG. 2 , display  200  with an aspect ratio of 4:3 is displaying an image of the video stream  201  with an aspect ratio of 1.33:1. Thus, display  200  does not have the shadowed areas  212  or  222  of displays  210  and  220 . 
     Display  210  has an aspect ratio of 4:3 and is showing image of the video stream  211  with an aspect ratio of 1.85:1. Because the video aspect ratio is greater than the display aspect ratio, horizontal shadow areas  212  are shown when the image of the video stream  211  is centered on display  210 . Display  220  has an aspect ratio of 4:3 and is showing letterbox image of the video stream  221  with an aspect ratio of 2.35:1. Because the video aspect ratio is greater than the display aspect ratio, horizontal shadow areas  222  are shown, when the image of the video stream  221  is centered on display  220 . 
     Display  230  has an aspect ratio of 16:9 and is showing image of the video stream  231  with an aspect ratio of 1.33:1. Because the video aspect ratio is smaller than the display aspect ratio, vertical shadow areas  232  are shown when the image of the video stream  231  is centered on display  230 . Display  240  has an aspect ratio of 16:9 and is showing letterbox image of the video stream  241  with an aspect ratio of 1.85:1. Because the video aspect ratio is greater than the display aspect ratio, horizontal shadow areas  242  are shown, when the image of the video stream  241  is centered on display  240 . Display  250  has an aspect ratio of 16:9 and is showing image of the video stream  251  with an aspect ratio of 2.35:1. Because the video aspect ratio is greater than the display aspect ratio, horizontal shadow areas  252  are shown, when the image of the video stream  251  is centered on display  250 . 
       FIG. 2  shows that shadow areas  212 ,  222 ,  232 ,  242 , and  252  occur for both historically popular 4:3 screens as well as newer 16:9 wide screens. In either case, a mismatch between screen aspect ratio and image aspect ratio will result in bars, typically black, being displayed either to the left and right, or on top and bottom, of the centered image. In  FIG. 2 , shadow areas  212 ,  222 ,  232 ,  242 , and  252  are available for uncentering and shifting image of the video streams  211 ,  221 ,  231 ,  241 , and  251  respectively. Uncentering of the displayed image may also be applied to all other images whose aspect ratio is not the same as that of the display screen. 
       FIG. 3  shows volume space  300  of DVD video disk  110 . The volume space  300  is initially divided into three zones: volume and file structure  301 , DVD-video zone  302 , and DVD others zone  303 . DVD-video zone  302  is further divided into video manager VMG  310 , and a series of video title sets VTS  320 ,  330 , and  340 . 
       FIG. 4  shows that video manager VMG  310  is further subdivided into control data video manager information VMGI  311 , Video object Set VOBS for menu VMGM_VOBS  312 , and the backup for the VMGI  313 . Each video title set is further subdivided. For example VTS # 1   320  is further subdivided into control data video title set information VTSI  321 , VOBS (video object set) for video title set menu VTSM_VOBS  322 , VOBS for video object set for titles in a VTS VTSTT_VOBS  323 , and backup for VTSI  324 . 
       FIG. 5  shows the internal structure of control data video title set information VTSI  321 , which is read from DVD video disk  110  before any video steam is displayed. Control data video title set information VTSI  321  contains video title set information management table VTSI_MAT  410 . Video title set information management table VTSI_MAT  410  contains video attribute of VTS VTS_V_ATR  420 . Video attribute of VTS VTS_V_ATR  420  contains a field which defines the video compression mode  421 , TV system  422 , aspect ratio of the video  423 , and display mode  424 . Video compression mode  421  is typically the MPEG encoding of the video stream, such as MPEG 1, 2, or 4. Video compression mode  421  is used by video decoder  123  to properly decode the encoded video stream. The aspect ratio of the video  423  is used in the present invention to obtain the aspect ratio of the video data (explained below with reference to flowchart  600  of  FIG. 6 ). 
     The image of the video stream shown on display  130  may be in letterbox format, where video  131  is between non-video zones  132 . Non-video zones  132  are typically black, but may be any color. Non-video zones  132  may also be referred to as shadow zones. Remote control device  140  may be used to control various display system attributes, in particular in this case controlling the position of the displayed image via the position button  141  and the direction-and-center button  142 . 
     One embodiment of this invention uses machine executed instructions to shift the display of the video stream letterbox view for each viewing session, so that the display of the video stream would not always be centered on the display screen. Shifting the display of the video stream letterbox view for each viewing session would place all pixels of the display in use when averaged over many viewing sessions. In this embodiment, the display of the video stream would not float around the screen in a manner similar to a screen saver. For each viewing session, the display of the video stream would remain in the initially determined screen location. 
     A second embodiment of this invention allows the user to select the video location. Smaller children may enjoy the video stream being displayed on the bottom of the display screen, because it would be closer to their line-of-sight. Similarly, adults may enjoy the video stream being displayed on the top of the display screen, to match the line-of-sight of an adult. The selection of the position to display the video stream on the display could be accomplished at system setup by choosing a default screen position as an alternative to enabling the system determine the position on the display via machine executed instructions. An override of either the default or system-determined display position could be accomplished dynamically via remote control buttons. An example of such buttons is shown on the remote control depicted in  140  in  FIG. 1 . The position button  141  could be pressed followed by either one of the arrow or center buttons  142  to place the image of the video stream at the desired location. As shown in  FIG. 1 , button  142  is a rocker button, which may be rocked to effect the up, down, left, and right arrows. If button  142  is pressed down rather than rocked, the image would be centered on the screen. Button  142  could be subdivided into separate up, down, left, right, and center buttons, if desired. This user-selected position of the display of the video stream could remain in effect for the duration of the current video session, or until the user selected a different image position. 
     To more fully explain the operation of the present invention reference is made to flowchart  600  shown in  FIG. 6 . Flowchart  600  begins at step  602  with start of program or power on. Step  602  flows to step  604 , where the aspect ratio of the display is obtained. The aspect ratio of the display is typically 4:3 or 16:9 as shown in  FIG. 2 ; however different aspects ratios may be used with the present invention, without limitation. The aspect ratio of the display may be obtained by various means. For example, the aspect ratio of the display may be obtained from an entry by an operator using remote control  140  anytime during the operation of display system  100 . Display system  100  receives the aspect ratio of the display from remote control  140  when processor  125  receives input from remote control  140  via remote uplink  12 . The aspect ratio of the display may be obtained from an entry by an operator using remote control  140  in response to a setup menu request during a step up procedure of display system  100 . The aspect ratio of the display could be preprogrammed into display system  100  or transmitted from display  130  to display system  100  as part of a power up sequence. For example, display  130  may use information bearing medium  199  to store the aspect ratio of display  130 . Information bearing medium  199  may be queried by processor  125 , so that processor  125  may determine the aspect ratio of the video stream. Alternately, processor  125  may access display library  198  which has the aspect ratios of known displays stored for recall. The user may access this library via remote  140  and toggle until the correct aspect ratio for display  130  is shown. 
     Step  604  then flows to step  606 , where the aspect ratio of the video stream is obtained. If the source of the displayed video is a DVD video disk (i.e. disk  110 ), then the aspect ratio of the video stream is preferably the aspect ratio  423  as read from DVD video disk  110 . The aspect ratio of the video stream may be obtained from the DVD video disk. For example, the aspect ratio of the video stream may be obtained from aspect ratio  423  by player  101  reading control data video title set information (VTSI)  321  from disk  110  before the video stream is read, decoded, and displayed. If the source of the video is a VCR then the aspect ratio of the video stream from a VHS tape, may be obtained by, for example, processing the video signal using a processor (i.e. processor  125 ). Alternatively, if the source of the displayed video is from a source other than a DVD or if it is not possible to obtain aspect ratio  423  from the video stream then the aspect ratio of the video stream may be obtained by other means. The aspect ratio of the video stream may also be obtained from a remote control. For example, the aspect ratio of the video stream may be obtained by entry from an operator using remote control  140  in response to a setup menu request during a setup procedure of display system  100 . Display system  100  receives the aspect ratio of the video stream from remote control  140  when processor  125  receives input from remote control  140  via remote uplink  12 . The aspect ratio of the video stream could also be preprogrammed into display system  100 . Upon exiting step  606 , processor  125  has access to stored values or representations of the aspect ratio of both the video stream and the display. 
     The process then flows from step  606  to decision step  608 , to determine whether the aspect ratio of the display is different than the aspect ratio of the video stream. One example of equal aspect ratios is when the video aspect ratio is 1.33:1 and the display aspect ratio is 4:3. A second example of equal aspect ratios is when the video aspect ratio is 1.78:1 and the display aspect ratio is 16:9. It is sufficient that this equality is determined only to the second decimal place. If at step  608 , the video stream aspect ratio is the same as the display aspect ratio, then the process flows to step  610  where the image of the video stream is displayed on the display without further processing. When the aspect ratios are the same, there are no shadow zones to shift the image of the video stream to, because the size of the image of the video stream matches the size of the display. 
     If the aspect ratio of the display and the video stream are different at step  608 , the process flows to step  612  where the determination is made whether the aspect ratio of the video stream is larger than the aspect ratio of the display. If at step  612 , the aspect ratio of the video stream is larger than the aspect ratio of the display, then the process flows to step  614 . At step  614  the process transfers to step  702  of flowchart  700  shown in  FIG. 7  to determine the vertical shift of the image of the video stream on the display to uncenter the image (explained below). 
     If at step  612 , the video aspect ratio is not larger than the display aspect ratio, the process flows to step  616 . From step  616 , the process branches to step  802  of  FIG. 8  to determine the horizontal shift of the image of the video stream on the display (explained below). 
     Flowchart  700  shown in  FIG. 7  illustrates a method to shift the image of the video stream on a display (i.e. display(s)  130 ,  210 ,  220 ,  240 ,  250 ) where there are available shadow areas  212 ,  222 ,  242 ,  252  (see  FIG. 2 ) for vertically uncentering the image of the video stream to produce a vertical shift of the image on the display. The process of flowchart  700  is executed in response to determining that the aspect ratio of the display is different than the aspect ratio of the video stream. Execution of the process of flowchart  700  results in positioning the image of the video stream on the display to uncenter the image on the display. Uncentering of the image of the video stream on the display is the result of any shift in the image from the exact center of the display. Processor  125  may be used to execute instructions to implement the process of flowchart  700  or  800 . The process flows to decision step  704 , to determine whether to apply a positioning algorithm or use the selected setup position to vertical shift the image of the video stream on the display. If at step  704  the decision is to not use the setup value, then the process flows to step  706 , where the positioning algorithm is used to select a screen position. If at step  704  the decision is to use the setup value, then the process flows to step  708 , where the set up value is used to select a screen position. 
     At step  706  a vertical shifting algorithm is chosen to automatically shift the image of the video stream on the display. In one embodiment the automatic shift of the image of the video stream on the display may be accomplished by selecting a random position of the image on the display at a selected interval and the displaying the image on the display at the random position. The selected interval may be for example the interval between power up cycles of a display system, each time a new video source is inserted (i.e. each time a DVD disk is played), at a user selected interval, at a random interval determined by a processing element (i.e. processor  125 ), each time the video is paused, etc. In one example of this embodiment the vertical shifting algorithm comprises selecting a random vertical shift integer, S v  between −N*I and N*I, where I is an increment number to modify the granularity of the shift and N is preferably an even number that is the normalized total amount of vertical shift necessary to eliminate one of shadow areas  212 ,  222 ,  242  or  252 . The vertical shift integer, S v  may be selected using techniques of random number generation as is known in the art, resulting in a range of N*I≦S v .≦N*I. A vertical shift integer, S v  value of n results in a position the image n/(N*I) increments up/down from the center. Thus, a vertical shift integer, S v  value of −N*I results in the position of the image of the video stream shifted to the top of the display, while a vertical shift integer, S v  value of +N*I results in the position of the image of the video stream shifted to the bottom of the display. A vertical shift integer, S v  value of 0 results in the position of the image of the video stream being in the center of the display. In a preferred embodiment N is determined by dividing the total height of one shadow area by the total height of the display and then taking the integer value. A typical value of increment number, I, is 100. In equation form: N=Integer value (shadow height/display height). The resulting percentage shift of the display, shift percentage=S v /I. For example if in  FIG. 2 , shadow area  212  is 20% of the total display height, area  211  is 60% of the total display height and choosing I=100, then N*I=Integer value (100*0.2/(0.2+0.2+0.6)), resulting in N*I =20. If S v .=−20 then the image of the video stream is shifted to the top of the display. If S v =10 then the image of the video stream is shifted down from center by a shift percentage=10/I or 10% of the display area. For this example, random values of S v  are chosen from the range of −20≦S v ≦20 to produce a vertical shift of +/−20% resulting in the image of the video stream covering a range of the top of the display to the bottom of the display but never resulting in a loss of any portion of the image on the display. Alternatively, instead of using a random number generator to choose the values of S v , S v  may be chosen by incrementing through the entire range of S v , one step at a time for each time the system is powered on. For example, upon the first power up of display system  100 , a value of −20 may be chosen for S v , upon the next power up the value of −19 may be chosen for S v , continuing on until S v =20, and then starting again at −20 on the next power up to repeat the entire sequence. 
     If at step  704 , the setup value to shift the image on the display is chosen, then the process flows to step  708 , where the value entered on a setup screen is used for vertical shift integer, S v . The discussion above for the range of vertical shift integer, S v  applies. The default value for the setup position may result in a value of S v =0, or other default values may be used without limitation. A user of display system  100  would have the option to change the default value for S v  or enter any value for at any time. The setup screen may prompt the user for an input value of S v , and only accept valid values for S v  to ensure that the system could operate properly. After execution of either of steps  706  or  708  control flows to step  710  where the image is placed at a position determined by the shift resulting from the execution of either of steps  706  or  708 . This shift is preferably accomplished in display buffer  124  by calculations executed by processor  125 . Control then flows to step  712  to display the image of the video stream on the display. Alternatively, a setup screen may not be used. A user may use the remote control to interrupt the display of the image at any time (See Flowchart  900 ). In the preferred embodiment, display system  100  receives a position from a remote control that results in displaying the image on the display at a position determined by the received position from the remote control. 
     If the execution of step  616  resulted in the execution of step  618 , then control transfers to step  802  of flowchart  800  to shift the image of the video stream in a horizontal direction. The process of flowchart  800  is executed in response to determining that the aspect ratio of the display is different than the aspect ratio of the video stream. Execution of the process of flowchart  800  results in positioning the image of the video stream on the display to uncenter the image on the display. Uncentering of the image of the video stream on the display is the result of any shift in the image from the exact center of the display. Flowchart  800  in  FIG. 8  illustrates a process for shifting of the image of the video stream where there are available shadow areas  232  for horizontally uncentering the image of the video stream. Upon entering step  802 , the process flows to decision step  804 , to determine whether to apply a positioning algorithm or use the selected setup position to horizontal shift the image of the video stream on the display. If at step  804 , the decision is to not use the set up value, then the process flows to step  806 , where the positioning algorithm is used to select a screen position. If at step  804  the decision is to use the setup value, then the process flows to step  808 , where the setup value is used to select a screen position. 
     At step  806  a horizontal shifting algorithm is chosen to automatically shift the image of the video stream on the display. In one embodiment the horizontal shifting algorithm comprises selecting a random horizontal shift integer, S h  between −N*I and N*I, where I is an increment number to modify the granularity of the shift and N is preferably an even number and is the normalized total amount of horizontal shift necessary to eliminate one of shadow areas  232  The horizontal shift integer, S h  may be selected using techniques of random number generation as is known in the art, resulting in a range of N*I≦S h .≦N*I. A horizontal shift integer, S h  value of n results in a position of the image n/(N*I) increments left/right from the center. Thus, a horizontal shift integer, S h  value of −N*I results in the position of the image of the video stream shifted to the left of the display, while a horizontal shift integer, S h  value of +N*I results in the position of the image of the video stream shifted to the right of the display. A horizontal shift integer, S h  value of 0 results in the position of the image of the video stream being in the center of the display. In a preferred embodiment, N is determined by dividing the total width of one shadow area by the total width of the display and then taking the integer value. A typical value of increment number I may be 100. In equation form: N=Integer value (shadow width/display width). The resulting percentage shift of the display, shift percentage=S h /I. For example, if in  FIG. 2 , shadow area  232  is 30% of the total display width and area  231  is 40% of the total display width and choosing I=100, then N*I=Integer value (100*0.3/(0.3+0.3+0.4)), resulting in N*I =30. If S h =−30 then the image of the video stream is shifted to the left portion of the display producing no shadow area on the left but a larger shadow area on the right. If S h =10 then the image of the video stream is shifted right from center by a shift percentage=10/I or 10% of the display area. For this example, random values of S h  are chosen from the range of −30≦S h ≦30 to produce a horizontal shift of +/−30% resulting in the image covering a range of the left of the display to the right of the display but never resulting in a loss of any portion of the image on the display. Alternatively, instead of using a random number generator to choose the values of S h , S h  may be chosen by incrementing through the entire range of S h , one step at a time for each time the system is powered on. For example, upon the first power up of display system  100 , a value of −30 may be chosen for S h , upon the next power up the value of −29 may be chosen for S h , continuing on until S h =30, and then starting again at −30 on the next power up to repeat the entire sequence. 
     If at step  804 , the setup value to shift the image on the display is chosen, then the process flows to step  808 , where the value entered on a setup screen or a default value is used for S h . The discussion above for the range of S h  applies. One of the components of display system  100  (i.e. display buffer  124 ) may receive a default position from a processor (i.e. processor  125 ) of display system  100  causing the displaying the image on the display at a position determined by the default position. The default value for the setup position may result in a value of S h =0, or other default values may be used without limitation. 
     A user of display system  100  would have the option to change the default value for S h  or enter any value at any time. The setup screen may prompt the user for an input value of S h , and only accept valid values for S h  to ensure that the system would operate properly. After execution of either of steps  806  or  808 , control flows to step  810  where the image of the video stream is placed at a position determined by the shift resulting from the execution of either of steps  806  or  808 . This shift is preferably accomplished in display buffer  124  by calculations executed by processor  125 . Control then flows to step  812  to display the image of the video stream on the display. Alternatively, a setup screen may not be used. A user may use the remote control to interrupt the display of the image at any time (See Flowchart  900 ). In the preferred embodiment display system  100  receives a position from a remote control that results in displaying the image on the display at a position determined by the received position from the remote control. 
     Flowchart  900 , shown in  FIG. 9  shows processing for a remote control interrupt. The process of flowchart  900  may be used anytime input from remote control  140  is used by display system  100 . The process of flowchart  900  may be implemented by processor  125 , other components within display system  100 , remote control  140  or associated components. Step  902  begins when a button on the remote control  140  is pressed, for example to input the position to display the image of the video stream on a display (i.e. steps  708 ,  808 ). The process flows to decision step  904 , to determine if the button pressed was the position button  141  or another button. If position button  141  was not pushed or activated, then step  904  transfers control to step  910 , where the process exits. If position button  141  was pushed or activated, then step  904  transfers control step  908 , where the image of the video stream is positioned at top, bottom, left, right, or center, of a display according to, respectively, the up, down, left, right, or center button  142  being pressed. The process then flows from step  908  to step  910 , which exits the remote control interrupt processing. Similar processing for dynamic user-selected positioning could also be done via a touch screen feature where the touch screen may be part of remote control  140 , display system  100 , display  130  or other components within display system  100 . Voice activation may also be used to input position information for the display of the image. Voice recognition elements may be used to process voice commands to move the image on the display. The voice recognition elements may be coupled to or located within remote control  140 , display system  100 , display  130  or another component of display system  100 . The voice activation could operate by receiving a position from a voice input from the voice activation element and displaying the image on the display at a position determined by the position from the voice input. For example, a user may say “move the image down” and the image would move down by a fixed increment (i.e. vertical shift integer, S v ). Other voice commands may be processed by the voice activation element to move the image in any direction. 
       FIG. 10  shows display  130  with image of the video stream  131  where the image of the video stream has a larger aspect ratio than the display. If centered, image of the video stream  131  is between non-video shadow zones  132 . This is assuming that the user has either selected centering at setup or dynamically selected a centered position using the remote control. If either at setup, via remote control, or via the positioning algorithm, the image is selected to be positioned at the top of the screen, then the image of the video stream  1031  is shown at the top of display  130 , and expanded shadow zone  1032  is shown at the bottom of display  130 . Shadow zone  1032  of the uncentered image of the video stream  1031  is the total size of previous shadow zones  132  of the centered image of the video stream  131 . 
     The choice of displayed video aspect ratio of a DVD video disk  110  is typically made by the user when the video disk is first loaded into the DVD player. When the choice is made in viewing mode, such as the generic “letterbox” mode where the aspect ratio of the video stream is larger than the display, the exact aspect ratio of the video may be read from the DVD disk using aspect ratio  423 . In a preferred embodiment as shown in flowcharts  600 ,  700 , and  800  the user could allow the image of the video stream to be positioned other than centered for viewing, depending on the aspect ratio of the display and the image of the video stream. The image of the video stream could be displayed in the chosen position for the duration of the power-on period. The chosen video position could alternately be re-selected at other intervals, such as a channel changes or on midnight crossings. The selection of image of the video stream location could be done in the television itself, where it would apply to all image sources, including cable, satellite, and over the air broadcasts, or in either the DVD player or a VHS player if the video stream is stored on tape. 
     This uncentering of the image of the video stream could be constant for the entire power-on period of the display, or for some other determined period, in order lengthen pixel life. This would be implemented by a simple horizontal or vertical “DC offset” to the pixel mapping onto the viewing screen. This offset to the pixel mapping would typically occur in display buffer  124  of  FIG. 1 . 
     The foregoing description, for purposes of explanation, used specific nomenclature to provide a thorough understanding of the invention. However, it will be apparent to one skilled in the art that the specific details are not required in order to practice the invention. In other instances, well known circuits and devices are shown in block diagram form in order to avoid unnecessary distraction from the underlying invention. Thus, the foregoing descriptions of specific embodiments of the present invention are presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed. Obviously many modifications and variations are possible in view of the above teachings. 
     The logic of  FIGS. 6-9  describes specific operations occurring in a particular order. In alternative implementations, certain of the logic operations may be performed in a different order, modified or removed. Moreover, steps may be added to the above described logic and still conform to the described implementations. Further, operations described herein may occur sequentially or certain operations may be processed in parallel, or operations described as performed by a single process may be performed by distributed processes. 
     The logic of  FIGS. 6-9  was described as being implemented in software. This logic may be part of the operating system of display system  100  or an application program. In yet further implementations, this logic may be maintained in storage areas managed by display system  100  or in a read only memory or other hardwired type of device. The preferred logic may be implemented in hard disk drives or in programmable and non-programmable gate array logic. Processor  125  may be configured to implement logical processing to implement the present invention. 
     The invention disclosed herein may be implemented as a method, apparatus or article of manufacture using standard programming and/or engineering techniques to produce software, firmware, hardware, or any combination thereof. The term article of manufacture as used herein refers to code or logic implemented in hardware logic (e.g., an integrated circuit chip, Programmable Gate Array (PGA), Application Specific Integrated Circuit (ASIC), etc.) or a computer readable medium (e.g., magnetic storage medium, hard disk drives, floppy disks, tape, etc.), optical storage (CD-ROMs, optical disks, etc.), volatile and non-volatile memory devices (e.g., HEPROMs, ROMs, PROMs, RAMs, DRAMs, SRAMs, firmware, programmable logic, etc.). Code in the computer readable medium is accessed and executed by a processor. The code may further be accessible through a transmission media or from a file server over a network. Of course, those skilled in the art will recognize that many modifications may be made to this configuration without departing from the scope of the present invention, and that the article of manufacture may comprise any information bearing medium known in the art. 
     The embodiments were chosen and described in order to best explain the principles of the invention and its practical applications, to thereby enable others skilled in the art to best utilize the invention and various embodiments with various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the following claims and their equivalents.