Image processing device, and image processing method, and program

An image processing device comprising an image signal correction unit that executes correction processing for a pixel signal of an input image,

• wherein the image signal correction unit inputs, as the input image, a mosaic image in which pixel blocks configured of a plurality of same-color pixels are arrayed,
• from among constituent pixels of the input image, detects pixel value gradients in eight directions in a conversion-target pixel location that is targeted for color conversion processing,
• decides an interpolated pixel value calculation mode for the conversion-target pixel on the basis of the pixel value gradients in the eight directions, and
• calculates an interpolated pixel value for the conversion-target pixel location in accordance with the decided processing mode;
• wherein the image signal correction unit,
• in the calculation processing for the pixel value gradients in the eight directions,
• when calculating a gradient in at least one direction,
• calculates a low-frequency component gradient in which pixels of the same color included in the input image are applied,
• a high-frequency component gradient in which pixels of the same color included in the input image are applied, and
• a mid-frequency component gradient in which pixels of the same color included in the input image are applied, and calculates a pixel value gradient by weighted addition of the three items of gradient information.

An image processing device comprising an image signal correction unit that executes correction processing for a pixel signal of an input image,

• wherein the image signal correction unit inputs, as the input image, a mosaic image in which pixel blocks configured of a plurality of same-color pixels are arrayed,
• from among constituent pixels of the input image, detects pixel value gradients in eight directions in a conversion-target pixel location that is targeted for color conversion processing,
• decides an interpolated pixel value calculation mode for the conversion-target pixel on the basis of the pixel value gradients in the eight directions, and
• calculates an interpolated pixel value for the conversion-target pixel location in accordance with the decided processing mode,
• wherein the image signal correction unit,
• in the calculation processing for the pixel value gradients in the eight directions,
• when calculating gradients in a vertical direction and a horizontal direction,
• calculates low-frequency component gradient information in which pixels of the same color included in the input image are applied,
• high-frequency component gradient information in which pixels of the same color included in the input image are applied, and
• different-color component gradient information in which pixels of different colors included in the input image are applied, and calculates a pixel value gradient by weighted addition of the three items of gradient information,
• when calculating gradients in a top-right 45-degree direction and a bottom-right 45-degree direction,
• calculates low-frequency component gradient information in which pixels of the same color included in the input image are applied,
• high-frequency component gradient information in which pixels of the same color included in the input image are applied, and
• mid-frequency component gradient information in which pixels of the same color included in the input image are applied, and calculates a pixel value gradient by weighted addition of the three items of gradient information,
• and when calculating gradients in a top-right 22.5-degree direction, a bottom-right 22.5-degree direction, a top-right 67.5-degree direction, and a bottom-right 67.5-degree direction,
• calculates low-frequency component gradient information in which pixels of the same color included in the input image are applied, and
• high-frequency component gradient information in which pixels of the same color included in the input image are applied, and calculates a pixel value gradient by weighted addition of the two items of gradient information.