Method and apparatus for determining the position of eyes and for correcting eye-defects in a captured frame

An apparatus for determining the position of eyes within a frame of captured image data comprising:

• means for capturing at least two color frames of an image scene, said means is provided with an optical lens defining an optical axis;
• means for storing the data of at least two consecutive captured frames of an image scene;
• an illumination source for illuminating one of said captured frames of said image scene wherein said illumination source is positioned as close as possible to said optical axis;
• and
• electronic means:
• a) for compensating said frames for the overall illumination change between said two captured frames to obtain a compensated frame;
• b) for determining the difference between said compensated frame and an uncompensated frame of said two captured frames to obtain a compensated color difference image;
• c) for scanning said compensated color difference image and determining pairs of regions of high intensity pixel value in at least one color channel;
• and
• d) for outputting the data of pixel pair coordinates wherein each coordinate corresponds to a center of each region of high intensity pixel value in said color channel within said captured image scene.

A method, used in a digital camera, for locating eye-defect regions comprises the steps of:

• selecting a function of the digital camera for eye-defect free picture taking;
• capturing two color frames of an image scene with a minimum delay in between to minimize spatial registration error, wherein one frame is captured with an ambient illumination and the other frame is captured with an additional camera triggered illumination;
• storing data, representing said two captured frames in a memory;
• compensating said frames for the overall illumination change between said two captured frames to obtain a compensated frame;
• determining the difference between said compensated frame and an uncompensated frame of said two captured frames to obtain a compensated color difference image;
• scanning said compensated color difference image and determining pairs of regions of high intensity pixel value in at least one color channel;
• and
• obtaining the data of pixel pair coordinates of said regions of bright intensity pixel value wherein each coordinate corresponds to a center of each of said eye-defect regions.

A digital camera capable of locating eye-defect regions comprising:

• a user input control for initiating the eye-defect correction function of the digital camera;
• means for capturing two color frames of an image scene with a minimum delay between to minimize spatial registration error, wherein said capturing means is provided with an optical lens defining an optical axis;
• an illumination source for illuminating one of the two frames of said image scene wherein said illumination source is positioned as close as possible to said optical axis;
• means for storing the data of said two captured frames of said image scene;
• and
• electronic means:
• for compensating said frames for the overall illumination change between said two captured frames to obtain a compensated frame;
• for determining the difference between said compensated frame and an uncompensated frame of said two captured frames to obtain a compensated color difference image;
• and
• for scanning said compensated color difference image and thereby determining pairs of regions of eye-defect, and for calculating spatial coordinates of said eye-defects.

A method, used in a photographic film camera, for locating eye-defect regions comprising the steps of:

• selecting a function of the photographic film camera for eye-defect free picture taking;
• exposing the photographic film with a frame of an image scene bearing the camera triggered illumination and simultaneously storing data of said frame bearing the camera triggered illumination in a memory;
• capturing a further frame of said image scene with a minimum delay in between to minimize spatial registration error, wherein said frame is captured with an ambient illumination, and storing data representing said frame in said memory;
• compensating said frames for the overall illumination change between said two captured frames to obtain a compensated frame;
• determining the difference between said compensated frame and an uncompensated frame of said two captured frames to obtain a compensated color difference image;
• scanning said compensated color difference image and determining pairs of regions of high intensity pixel value in at least one color channel;
• obtaining data of pixel pair coordinates corresponding to the pairs of regions of high intensity pixel value wherein each coordinate corresponds to a center of each of said eye-defect regions;
• and
• recording on the photographic film inside the camera coordinates of said pairs of regions of high intensity pixel value preferably in the red channel.

A photographic film camera capable of locating eye-defects comprises:

• a user input control for initiating the eye-defect free function of the film camera;
• means for capturing two frames of an image scene with a minimum delay between to minimize spatial registration error, wherein said capturing means is provided with an optical lens defining an optical axis;
• an illumination source for illuminating one of said two frames of said image scene, wherein said illumination source is positioned as close as possible to said optical axis;
• a photographic film for capturing said illuminated frame of said image scene, said film including a recording layer;
• means for temporarily storing data of said illuminated frame and data of said frame bearing ambient illumination of said image scene;
• electronic means
• for compensating said frames for the overall illumination change between said two captured frames to obtain a compensated frame;
• for determining the difference between said compensated frame and an uncompensated frame of said two captured frames to obtain a compensated color difference image;
• for scanning said compensated color difference image and thereby determining pairs of regions of eye-defect, and calculating spatial coordinates of said eye-defects;
• and
• recording means for writing the spatial coordinates of the eye-defects in said recording layer on said photographic film inside said photographic film camera.