Patent ID: 8000563
Filing Date: 2011-08-16
Classification: G06T,G09G,H04N

Abstract:
1. An interpolation device that determines pixel values of m types of colors of an interpolation point Q at any position on an XY coordinate system by interpolation calculation based on individual pixel values obtained by an image pickup apparatus, in which a total of m types of light receiving elements, each having functions of detecting, in regard to a received light, a light amount of a specific color and outputting the light amount as a pixel value, are respectively positioned periodically according to predetermined regular patterns at positions of specific lattice points on a square lattice defined on the XY coordinate system, the interpolation device comprising: a pixel value input unit that inputs the pixel values output from the individual light receiving elements that constitute the image pickup apparatus; a pixel value storage unit that stores the input pixel values in a form of a pixel value array, with which the pixel values are associated with positions of respective lattice points; an interpolation point designating unit that, in regard to the interpolation point Q for which pixel values are to be determined by interpolation calculation, determines a smallest square which contains the interpolation point Q and whose four vertices are constituted by the lattice points, as a position reference frame, determines, as a position origin α, a vertex, which, among the four vertices constituting the position reference frame, occupies a relative position that has been determined in advance, and designates a position of the interpolation point Q by an upper address (X, Y) that indicates a position of the position origin αin the square lattice and a lower address (x, y) that indicates the position of the interpolation point Q in an xy coordinate system defined as a local coordinate system inside the position reference frame; a calculation target color designating unit that designates one of the m types of colors in turn as a calculation target color for which a pixel value is to be computed; an interpolation reference frame determining unit that uses the upper address (X, Y) and the lower address (x, y) and a regular pattern of the calculation target color designated by the calculation target color designating unit to determine an interpolation reference frame, formed of a smallest square which contains the interpolation point Q and whose four vertices are constituted by lattice points, at which are positioned pixels corresponding to light receiving elements having a function of detecting the calculation target color, and determining, as an interpolation origin β, a vertex, which, among the four vertices forming the interpolation reference frame, occupies a relative position that has been determined in advance; an interpolation proportion determining unit that, when a direction parallel to a first pair of opposing sides that constitute the interpolation reference frame is set as a first direction and a direction parallel to a second pair of opposing sides is set as a second direction, determines a distance d between the interpolation origin β and the interpolation point Q in regard to the first direction and a distance e in regard to the second direction on a basis of the upper address (X, Y) and the lower address (x, y) and determines values d* and e* , with which the determined distances d and e are normalized by a length of a side of the interpolation reference frame, respectively as an interpolation proportion in regard to the first direction and an interpolation proportion in regard to the second direction; and an interpolation calculation unit that reads the pixel values of at least the light receiving elements positioned at the four vertices of the interpolation reference frame as interpolation reference values from the pixel value storage unit and performs an interpolation calculation based on the interpolation reference values and the interpolation proportions d* and e* to determine a pixel value of the interpolation point Q for each calculation target color.