# US 8,786,598 B2 · Pixel-intensity modulation technique for frame-sequential stereo-3D displays > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,786,598 B2 - Document ID: US8786598B2 - Status: Granted - Kind: B2 - Application number: 12/950,753 - Filed: 2010-11-19 - Published: 2012-05-24 - Granted: 2014-07-22 - Earliest claimed: 2010-11-19 - Assignees: ATI Technologies ULC - Applicants: Philip L. Swan - Inventors: Philip L. Swan - Web page: https://patentgrep.com/patent/US8786598B2 ## CPC - H04N 13/139: Format conversion, e.g. of frame-rate or size - H04N 13/122: Improving the three-dimensional [3D] impression of stereoscopic images by modifying image signal contents, e.g. by filtering or adding monoscopic depth cues (H04N13/128 takes precedence) - H04N 13/341: using temporal multiplexing - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION ## Abstract Discloses herein are methods, apparatuses, and systems for preparing and displaying images in frame-sequential stereoscopic 3D. Frame-sequential stereoscopic display includes an alternating sequence of left- and right-perspective images for display. Disclosed methods include identifying pixels that modulate due to the alternating sequence of left- and right-perspective images of the frame-sequential stereoscopic display. The disclosed methods also include processing the pixels to reduce one or more residual images caused by the alternating sequence of left- and right-perspective images of the frame-sequential stereoscopic display. The disclosed methods may be implemented by a processing unit and the processing unit may be included in a system (such as, a computer or video-game console). ## Claims ### Claim 1 A method, comprising: arranging alternating first-perspective and second-perspective images for frame-sequential stereoscopic display into a sequence comprising a first string of multiple first-perspective images and a second string of multiple second-perspective images for display; altering a pixel intensity of a first boundary image in the first string, wherein the first boundary image is next to a boundary between the first string and the second string, such that the pixel intensity of the first boundary image is closer to a pixel intensity of a second boundary image in the second string, wherein the second boundary image is next to the boundary between the first string and the second string; and adjusting a pixel intensity of a second image in the first string such that an average pixel intensity of images in the first string remains substantially the same. ### Claim 2 (depends on 1) The method of claim 1, wherein the altering comprises reducing the pixel intensity of the first boundary image in the first string, and the adjusting comprises raising the pixel intensity of the second image in the first string. ### Claim 3 (depends on 1) The method of claim 1, wherein the altering comprises raising the pixel intensity of the first boundary image in the first string, and the adjusting comprises reducing the pixel intensity of the second image in the first string. ### Claim 4 (depends on 1) The method of claim 1, further comprising: adjusting the rate at which the first-perspective and second-perspective images are alternated to concentrate brightness of the images in fewer frames. ### Claim 5 A processing unit configured to perform operations comprising: arrange alternating first-perspective and second-perspective images for frame-sequential stereoscopic display into a sequence comprising a first string of multiple first-perspective images and a second string of multiple second-perspective images for display; alter a pixel intensity of a first boundary image in the first string, wherein the first boundary image is next to a boundary between the first string and the second string, such that the pixel intensity of the first boundary image is closer to a pixel intensity of a second boundary image in the second string, wherein the second boundary image is next to the boundary between the first string and the second string; and adjust a pixel intensity of a second image in the first string such that an average pixel intensity of images in the first string remains substantially the same. ### Claim 6 (depends on 5) The processing unit of claim 5, wherein the processing unit is further configured to alter the pixel intensity of the first boundary image by reducing the pixel intensity of the first boundary image in the first string and adjust the pixel intensity of the second image by raising the pixel intensity of the second image in the first string. ### Claim 7 (depends on 5) The processing unit of claim 5, wherein the processing unit is further configured to alter the pixel intensity of the first boundary image by raising the pixel intensity of the first boundary image in the first string and adjust the pixel intensity of the second image by reducing the pixel intensity of the second image in the first string. ### Claim 8 (depends on 5) The processing unit of claim 5, wherein the processing unit is further configured to adjust the rate at which the first-perspective and second-perspective images are alternated to concentrate brightness of the images in fewer frames. ### Claim 9 (depends on 5) The processing unit of claim 5, wherein the processing unit comprises a graphics processing unit. ### Claim 10 (depends on 5) The processing unit of claim 5, wherein the processing unit is further configured to determine whether the images are organized for frame-sequential stereoscopic display; and provide the images for display on a display device, wherein the images are displayed in stereoscopic 3D when the images are organized for frame-sequential stereoscopic display, and wherein the images are displayed in 2D when the images are not organized for frame-sequential stereoscopic display. ### Claim 11 A system, comprising: a processing unit configured to prepare images for frame-sequential stereoscopic display, wherein the preparation of the images for frame-sequential stereoscopic display includes arranging alternating first-perspective and second-perspective images for the frame-sequential stereoscopic display into a sequence comprising a first string of multiple first-perspective images and a second string of multiple second-perspective images for display, altering a pixel intensity of a first boundary image in the first string, wherein the first boundary image is next to a boundary between the first string and the second string, such that the pixel intensity of the first boundary image is closer to a pixel intensity of a second boundary image in the second string, wherein the second boundary image is next to the boundary between the first string and the second string, and adjusting a pixel intensity of a second image in the first string such that an average pixel intensity of images in the first string remains substantially the same; and a display configured to display the images prepared by the processing unit. ### Claim 12 (depends on 11) The system of claim 11, wherein the processing unit is further configured to alter the pixel intensity of the first boundary image by reducing the pixel intensity of the first boundary image in the first string and adjust the pixel intensity of the second image by raising the pixel intensity of the second image in the first string. ### Claim 13 (depends on 11) The system of claim 11, wherein the processing unit is further configured to alter the pixel intensity of the first boundary image by raising the pixel intensity of the first boundary image in the first string and adjust the pixel intensity of the second image by reducing the pixel intensity of the second image in the first string. ### Claim 14 (depends on 11) The system of claim 11, wherein the multiple images are refreshed at a rate of approximately 240 Hz and the first string and the second string are alternated at a rate of approximately 60 Hz. ### Claim 15 (depends on 11) The system of claim 11, wherein the first string and the second string each include four images. ### Claim 16 (depends on 11) The system of claim 11, wherein the processing unit is further configured to adjust the first-perspective and second-perspective images are alternated to concentrate brightness of the images in fewer frames. ### Claim 17 (depends on 11) The system of claim 11, wherein the processing unit comprises a graphics processing unit. ### Claim 18 (depends on 11) The system of claim 11, wherein the processing unit is further configured to determine whether the images are organized for frame-sequential stereoscopic display and provide the images for display on a display device, wherein the images are displayed in stereoscopic 3D when the images are organized for frame-sequential stereoscopic display, and wherein the images are displayed in 2D when the images are not organized for frame-sequential stereoscopic display. ### Claim 19 A computer-program product comprising a non-transitory computer-readable storage medium containing instructions that, if executed on a computing device, define a processing unit for preparing images for frame-sequential stereoscopic display, wherein the processing unit is configured to: arrange alternating first-perspective and second-perspective images for the frame-sequential stereoscopic display into a sequence comprising a first string of multiple first-perspective images and a second string of multiple second-perspective images for display; alter a pixel intensity of a first boundary image in the first string, wherein the first boundary image is next to a boundary between the first string and the second string, such that the pixel intensity of the first boundary image is closer to a pixel intensity of a second boundary image in the second string, wherein the second boundary image is next to the boundary between the first string and the second string; and adjust a pixel intensity of a second image in the first string such that an average pixel intensity of images in the first string remains substantially the same. ### Claim 20 (depends on 19) The computer-program product of claim 19, wherein the processing unit is further configured to alter the pixel intensity of the first boundary image by reducing the pixel intensity of the first boundary image in the first string and adjust the pixel intensity of the second image by raising the pixel intensity of the second image in the first string. ### Claim 21 (depends on 19) The computer-program product of claim 19, wherein the processing unit is further configured to alter the pixel intensity of the first boundary image by raising the pixel intensity of the first boundary image in the first string and adjust the pixel intensity of the second image by reducing the pixel intensity of the second image in the first string.