Patent ID: 8045826

Claim:
An image processing apparatus that receives mosaic image data having settings of only one color component, among three color components R, G, and B corresponding to three primary colors of light, in each pixel and makes the received mosaic image data subject to a series of image processing to generate an edge map that identifies pixels of the mosaic image data through which an edge passes, where the mosaic image data is expressed by a combination of pixel columns with alternate arrangement of pixels of the G component and pixels of the R component as another color component in a vertical direction, pixel columns with alternate arrangement of pixels of the G component and pixels of the B component as another color component in the vertical direction, pixel rows with alternate arrangement of pixels of the G component and pixels of the R component as another color component in a horizontal direction, and pixel rows with alternate arrangement of pixels of the G component and pixels of the B component as another color component in the horizontal direction, the image processing apparatus comprising: a vertical-direction color difference component computation module configured to obtain the G component in the pixel location of another color component or to obtain another color component in the G component pixel location using vertically neighboring available components in, order to compute a vertical-direction color difference component between the G component and another color component in each pixel included in each of the pixel columns of the mosaic image; a horizontal-direction color difference component computation module configured to obtain the G component in the pixel location of another color component or to obtain another color component in the G component pixel location using horizontally neighboring color components in order to compute a horizontal-direction color difference component between the G component and another color component in each pixel included in each of the pixel rows of the mosaic image; an edge detection module configured to select pixels from the mosaic image data, and in each such pixel location compare the sign of the vertical color difference component of the target pixel to the signs of the vertical color difference components of the pixels above and below the target pixel, compare the sign of the horizontal color difference component of the target pixel to the signs of the horizontal color difference components of the pixels to the left and to the right of the target pixel, set the corresponding edge map value of the edge map to 1 where the signs in one or more of the comparisons are not equal, and set the corresponding edge map value of the edge map to 0 where the signs in all of the comparisons are equal.