# US 7,746,385 B2 · Red-eye filter method and apparatus > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,746,385 B2 - Document ID: US7746385B2 - Status: Granted - Kind: B2 - Application number: 12/194,148 - Filed: 2008-08-19 - Published: 2009-01-29 - Granted: 2010-06-29 - Earliest claimed: 1997-10-09 - Assignees: FotoNation Vision Limited - Inventors: Eran Steinberg; Yury Prilutsky; Peter Corcoran; Petronel Bigioi; Michael J. DeLuca - Web page: https://patentgrep.com/patent/US7746385B2 ## CPC - H04N 1/62: Retouching, i.e. modification of isolated colours only or in isolated picture areas only - G06T 5/94: based on local image properties, e.g. for local contrast enhancement - G06T 7/90: Determination of colour characteristics - G06V 40/162: {using pixel segmentation or colour matching} - G06V 40/165: {using facial parts and geometric relationships} - G06V 40/193: {Preprocessing; Feature extraction} - H04N 1/6086: {by scene illuminant, i.e. conditions at the time of picture capture, e.g. flash, optical filter used, evening, cloud, daylight, artificial lighting, white point measurement, colour temperature} - H04N 1/624: {Red-eye correction (control of camera based on recognised facial parts H04N23/611)} - H04N 9/70: for colour killing - H04N 23/63: by using electronic viewfinders - H04N 23/74: by influencing the scene brightness using illuminating means - G06T 2207/10024: Color image - G06T 2207/30201: Face - G06T 2207/30216: Redeye defect - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION - G06T: IMAGE DATA PROCESSING OR GENERATION, IN GENERAL - G06V: IMAGE OR VIDEO RECOGNITION OR UNDERSTANDING ## Abstract A digital image acquisition system having no photographic film, such as a digital camera, has a flash unit for providing illumination during image capture and a red-eye filter for detecting a region within a captured image indicative of a red-eye phenomenon, the detection being based upon a comparison of the captured image and a reference image of nominally the same scene taken without flash. In the embodiment the reference image is a preview image of lower pixel resolution than the captured image, the filter matching the pixel resolutions of the captured and reference images by up-sampling the preview image and/or sub-sampling the captured image. The filter also aligns at least portions of the captured image and reference image prior to comparison to allow for, e.g. movement in the subject. ## Claims ### Claim 1 A digital image acquisition system having no photographic film, comprising a portable apparatus for capturing digital images, a flash unit for providing illumination during image capture, and a red-eye filter for detecting red-eye phenomenon in a captured image based upon a comparison of said captured image and a reference image of nominally the same scene taken without flash, wherein the red eye filter further includes an alignment filter configured to align for aligning at least portions of the captured image and reference image prior to said comparison, and to match the pixel resolutions of the captured and reference images by up-sampling the preview image or sub-sampling the captured image, or a combination thereof, wherein the red eye filter detects said red-eye phenomenon by identifying a region in the captured image having a color indicative of a red-eye phenomenon and comparing said identified region with the corresponding region in the reference image, wherein the red eye filter further designates said region as indicative of a red-eye phenomenon if said corresponding region does not have a color indicative of a red-eye phenomenon. ### Claim 2 A digital image acquisition system having no photographic film, comprising a portable apparatus for capturing digital images, a flash unit for providing illumination during image capture, and a red-eye filter for detecting red-eye phenomenon in a captured image based upon a comparison of said captured image and a reference image of nominally the same scene taken without flash, wherein the red eye filter further includes an alignment filter configured to align at least portions of the captured image and reference image prior to said comparison, wherein the red eye filter detects said red-eye phenomenon by identifying a region in the captured image having a color indicative of a red-eye phenomenon and comparing said identified region with the corresponding region in the reference image, wherein the red eye filter further designates said region as indicative of a red-eye phenomenon if said corresponding region does not have a color indicative of a red-eye phenomenon, and, wherein the decision as to whether a region has a color indicative of a red-eye phenomenon is determined on a statistical basis as a global operation on the entire region. ### Claim 3 A digital image acquisition system having no photographic film, comprising a portable apparatus for capturing digital images, a flash unit for providing illumination during image capture, and a red-eye filter for detecting red-eye phenomenon in a captured image based upon a comparison of said captured image and a reference image of nominally the same scene taken without flash, wherein the red eye filter is configured to detect said red-eye phenomenon by identifying a region in the captured image having a color indicative of a red-eye phenomenon and comparing said identified region with the corresponding region in the reference image, wherein the red eye filter further designates said region as indicative of a red-eye phenomenon if said corresponding region does not have a color indicative of a red-eye phenomenon, wherein the decision as to whether a region has a color indicative of a red-eye phenomenon is determined on a statistical basis as a global operation on the entire region. ### Claim 4 A digital image acquisition system having no photographic film, comprising a portable apparatus for capturing digital images, a flash unit for providing illumination during image capture, and a red-eye filter for detecting red-eye phenomenon in a captured image based upon a comparison of said captured image and a reference image of nominally the same scene taken without flash, wherein the red eye filter is configured to detect said red-eye phenomenon by identifying a region in the captured image having a color indicative of a red-eye phenomenon and comparing said identified region with the corresponding region in the reference image, wherein the red eye filter further designates said region as indicative of a red-eye phenomenon if said corresponding region does not have a color indicative of a red-eye phenomenon, wherein the decision as to whether a region has a color indicative of a red-eye phenomenon is determined on a statistical basis as a global operation on the entire region. ### Claim 5 A portable apparatus for capturing digital images, comprising optics and a sensor, a flash unit, a processor and a red eye filter, wherein the apparatus comprises processor-readable code embedded in one or more media for programming the processor to detect a red-eye phenomenon within a digital image captured by the apparatus, and to identify a region within a captured image indicative of a red-eye phenomenon by comparing said captured image and at least one reference eye color characteristic and at least one reference eye shape characteristic, wherein the red eye filter detects said red-eye phenomenon by identifying a region in the captured image having a color indicative of a red-eye phenomenon and comparing said identified region with the corresponding reference eye color characteristic, wherein the red eye filter further designates said region as indicative of a red-eye phenomenon if said corresponding region does not have a said reference eye color characteristic indicative of said red-eye phenomenon. ### Claim 6 (depends on 5) The apparatus of claim 5, wherein said at least one reference eye color characteristic comprises an eye color characteristic of a reference image of nominally the same scene taken without flash, and wherein the reference image is a preview image of lower pixel resolution than the captured image, the one or more media having code further for programming the processor to match the pixel resolutions of the captured and reference images by up-sampling the preview image or sub-sampling the captured image, or a combination thereof. ### Claim 7 (depends on 6) The apparatus of claim 6, wherein the one or more media having code further for programming the processor to align at least portions of the captured image and reference image prior to said comparing. ### Claim 8 (depends on 7) The apparatus of claim 7, wherein the one or more media having code further for programming the processor to analyze a shape and to identify a region in the captured image having both a shape and color indicative of a red-eye phenomenon for subsequent comparison with the corresponding region in the reference image. ### Claim 9 (depends on 7) The apparatus of claim 7, wherein the one or more media having code further for programming the processor to analyze a shape to determine subsequent to said comparison whether a region designated as indicative of a red-eye phenomenon has a shape indicative of a red-eye phenomenon. ### Claim 10 (depends on 6) The apparatus of claim 6, wherein said digital image acquisition system comprises a combination of a digital camera and an external processing device. ### Claim 11 (depends on 10) The apparatus of claim 10, wherein said red-eye filter is located in said external processing device. ### Claim 12 (depends on 6) The apparatus of claim 6, wherein the method further comprises modifying the color of the pixels within a region indicative of a red-eye phenomenon. ### Claim 13 (depends on 12) The apparatus of claim 12, wherein said at least one reference eye color characteristic comprises an eye color characteristic of a reference image of nominally the same scene taken without flash, and the one or more media having code further for programming the processor to align at least portions of the captured image and reference image prior to said comparison. ### Claim 14 (depends on 13) The apparatus of claim 13, wherein the one or more media having code further for programming the processor to analyze a shape so that the processor identifies a region in the captured image having both a shape and color indicative of a red-eye phenomenon for subsequent comparison with the corresponding region in the reference image. ### Claim 15 (depends on 14) The apparatus of claim 14, wherein the one or more media having code further for programming the processor to analyze a shape to determine subsequent to said comparison whether a region designated as indicative of a red-eye phenomenon has a shape indicative of a red-eye phenomenon. ### Claim 16 (depends on 12) The apparatus of claim 12, wherein the method further comprises detecting said region indicative of a red-eye phenomenon by identifying a region in the captured image at least having a color indicative of a red-eye phenomenon and comparing said identified region with the corresponding region in the reference image, and designating said region as indicative of a red-eye phenomenon if said corresponding region does not have a color indicative of a red-eye phenomenon. ### Claim 17 (depends on 5) The apparatus of claim 5, wherein the one or more media having code further for programming the processor to analyze a shape so that the processor identifies a region in the captured image having both a shape and color indicative of a red-eye phenomenon. ### Claim 18 (depends on 5) The apparatus of claim 5, wherein the one or more media further for programming the processor to analyze shape to determine whether a region designated as indicative of a red-eye phenomenon has a shape indicative of a red-eye phenomenon. ### Claim 19 (depends on 5) The apparatus of claim 5, wherein said digital image acquisition system comprises a digital camera. ### Claim 20 (depends on 5) The apparatus of claim 5, wherein the one or more media further method further comprises analysing a shape, so that the processor identifies a region in the captured image having both a shape and color indicative of a red-eye phenomenon for subsequent comparison with a reference eye shape characteristic and the reference eye color characteristic, respectively. ### Claim 21 (depends on 20) The apparatus of claim 20, wherein one or more media having code further for programming the processor to modify the color of the pixels within a region indicative of a red-eye phenomenon. ### Claim 22 (depends on 5) The apparatus of claim 5, wherein the one or more media having code further for programming the processor to modify the color of the pixels within a region indicative of a red-eye phenomenon. ### Claim 23 A portable apparatus for capturing digital images, comprising optics and a sensor, a flash unit, a processor and a red eye filter, wherein the apparatus comprises processor-readable code embedded in one or more media for programming the processor to detect a red-eye phenomenon within a digital image taken with flash and captured by the apparatus, and to identify a region within a captured image indicative of a red-eye phenomenon by comparing said captured image and at least one reference image taken without flash, and to detect said region indicative of a red-eye phenomenon by identifying a region in the captured image at least having a color indicative of a red-eye phenomenon and comparing said identified region with the corresponding region in the reference image, and designating said region as indicative of a red-eye phenomenon if said corresponding region does not have a color indicative of a red-eye phenomenon, and the one or more media further for programming the processor to determine whether a region has a color indicative of a red-eye phenomenon on a statistical basis as a global operation on the entire region.