Image signal processing device

An image signal processing device that outputs an image signal to a liquid crystal display device after processing image data of each frame of the image signal, comprising:

• a delay part to which image data of each frame of the image signal is input, and which outputs the image data after delaying the image data by a period of time corresponding to one frame;
• a basic correction value output part:
• to which:
• data G1[n−1:k] of high order (n−k) bits of image data G1[n−1:0] of n bits of a first frame to be output from the delay part, where n is an integer equal to or greater than four and k an integer equal to or greater than two and equal to or less than (n−2);
• and
• data G2[n−1:k] of high order (n−k) bits of image data G2[n−1:0] of n bits of a second frame to be input to the delay part are input;
• and
• which outputs:
• a basic correction value D1 corresponding to data (G1[n−1:k], G2[n−1:k]);
• a basic correction value D2 corresponding to data (G1[n−1:k], G2[n−1:k]+1);
• a basic correction value D3 corresponding to data (G1[n−1:k]+1, G2[n−1:k]);
• and
• a basic correction value D4 corresponding to data (G1[n−1:k]+1, G2[n−1:k]+1);
• and
• a corrected image data output part:
• to which:
• the image data G1[n−1:0] of n bits of the first frame to be output from the delay part;
• the image data G2[n−1:0] of n bits of the second frame to be input to the delay part;
• and
• basic correction values D1 to D4 output from the basic correction value output part are input;
• and
• which acquires corrected image data corresponding to data (G1[n:0], G2[n:0]) by interpolation calculation and outputs the corrected image data thus acquired to the liquid crystal display device, wherein
• the corrected image data output part acquires, when “G1[n−1:k]=G2[n−1:k]” holds for the high order (n−k) bits of the image data:
• the corrected image data by interpolation calculation based on the basic correction values D1, D2 and D4 when “G1[k−1:0]<G2[k−1:0]” holds for the low order k bits of the image data;
• the corrected image data by interpolation calculation based on the basic correction values D1, D3 and D4 when “G1[k−1:0]≧G2[k−1:0]” holds for the low order k bits of the image data;
• and
• the corrected image data by bilinear interpolation calculation based on the basic correction values D1 to D4 when “G1[n−1:k]≠G2[n−1:k]” holds for the high order (n−k) bits of the image data.