Pixel defect correction device, imaging apparatus, pixel defect correction method, and program

An imaging apparatus comprising:

• a pixel section including an imaging device which images a subject image;
• and
• a pixel defect correction device that receives image data from the imaging device and performs pixel defect correction processing,
• wherein the pixel defect correction device includes
• a defect determining section that determines whether or not a pixel of interest of an image, in which a plurality of pixels each having a pixel value are arrayed in a two-dimensional manner, is a defect of the image,
• a gradient detecting section that detects a gradient or an edge in a processing region, which includes a plurality of pixels with the pixel of interest in the middle, on the basis of values of at least peripheral pixels around the pixel of interest which are included in the processing region,
• a correction value acquisition section that selects a pixel, which is used for acquisition of a correction value of the pixel of interest, according to the detected gradient or edge and acquires the correction value from a value of the selected pixel, and
• a defective pixel replacing section that replaces the value of the pixel of interest with the correction value when the pixel of interest is determined to be a defect of the image,
• wherein the gradient detecting section detects the gradient or the edge of the processing region on the basis of a value of a peripheral pixel with a different color from the pixel of interest, and
• wherein in order to detect the gradient or the edge in the processing region, the gradient detecting section acquires gradients or edges for a plurality of directions in the processing region on the basis of a value of a peripheral pixel with a different color from the pixel of interest included in the processing region and selects a direction, which corresponds to the gentlest gradient or edge, from the acquired gradients or edges in the plurality of directions.

A pixel defect correction method comprising the steps of:

• determining whether or not a pixel of interest of an image, in which a plurality of pixels each having a pixel value are arrayed in a two-dimensional manner, is a defect of the image;
• detecting a gradient or an edge in a processing region, which includes a plurality of pixels with the pixel of interest in the middle, on the basis of values of at least peripheral pixels around the pixel of interest which are included in the processing region;
• selecting a pixel, which is used for acquisition of a correction value of the pixel of interest, according to the detected gradient or edge and acquiring the correction value from a value of the selected pixel;
• and
• replacing the value of the pixel of interest with the correction value when the pixel of interest is determined to be a defect of the image,
• wherein said detecting the gradient includes detecting the gradient or the edge of the processing region on the basis of a value of a peripheral pixel with a different color from the pixel of interest, and
• wherein said detecting the gradient includes acquiring gradients or edges for a plurality of directions in the processing region on the basis of a value of a peripheral pixel with a different color from the pixel of interest included in the processing region and selecting a direction, which corresponds to the gentlest gradient or edge, from the acquired gradients or edges in the plurality of directions.

A non-transitory computer readable medium storing a program that is executable by a computer to perform pixel defect correction processing including:

• defect determination processing for determining whether or not a pixel of interest of an image, in which a plurality of pixels each having a pixel value are arrayed in a two-dimensional manner, is a defect of the image;
• direction detection processing for detecting a gradient or an edge in a processing region, which includes a plurality of pixels with the pixel of interest in the middle, on the basis of values of at least peripheral pixels around the pixel of interest which are included in the processing region;
• correction value acquisition processing for selecting a pixel, which is used for acquisition of a correction value of the pixel of interest, according to the detected gradient or edge and acquiring the correction value from a value of the selected pixel;
• and
• replacement processing for replacing the value of the pixel of interest with the correction value when the pixel of interest is determined to be a defect of the image,
• wherein said direction detection processing detects the gradient or the edge of the processing region on the basis of a value of a peripheral pixel with a different color from the pixel of interest, and
• wherein said direction detection processing includes acquiring gradients or edges for a plurality of directions in the processing region on the basis of a value of a peripheral pixel with a different color from the pixel of interest included in the processing region and selecting a direction, which corresponds to the gentlest gradient or edge, from the acquired gradients or edges in the plurality of directions.