Depth signal generation apparatus, pseudo stereo image signal generation apparatus, depth signal generation method, pseudo stereo image signal generation method, computer-readable recording medium recording depth signal generation program, and computer-readable recording medium recording pseudo stereo image signal generation program

A depth signal generation method, comprising:

• generating a depth signal which expresses a depth for each pixel of a predetermined unit in a video image signal;
• dividing a range of a depth signal level which the depth signal can have, into a plurality of depth signal level regions each having a predetermined size, determining which depth signal level region includes the depth signal for each pixel of the predetermined unit, and counting the number of pixels included in each depth signal level region to generate depth signal histogram data which expresses a level distribution of the depth signal in the depth signal level regions, according to the counted number of pixels;
• calculating a dispersion value of the depth signal histogram data and calculating a gain correction value according to the dispersion value;
• generating points for generating a depth signal level conversion curve to be used to perform level conversion of the depth signal, according to the gain correction value;
• generating interpolation data which interpolates between the points in the depth signal level conversion curve;
• and
• generating the depth signal level conversion curve using the points and the interpolation data to perform the level conversion of the depth signal using the depth signal level conversion curve.

A computer readable non-transitory recording medium recording a depth signal generation program therein for causing a computer to execute a method comprising:

• generating a depth signal which expresses a depth for each pixel of a predetermined unit in a video image signal;
• dividing a range of a depth signal level which the depth signal can have, into a plurality of depth signal level regions each having a predetermined size, determining which depth signal level region includes the depth signal for each pixel of the predetermined unit, and counting the number of pixels included in each depth signal level region to generate depth signal histogram data which expresses a level distribution of the depth signal in the depth signal level regions, according to the counted number of pixels;
• calculating a dispersion value of the depth signal histogram data and calculating a gain correction value according to the dispersion value;
• generating points for generating a depth signal level conversion curve to be used to perform level conversion of the depth signal, according to the gain correction value;
• generating interpolation data which interpolates between the points in the depth signal level conversion curve;
• and
• generating the depth signal level conversion curve using the points and the interpolation data to perform the level conversion of the depth signal using the depth signal level conversion curve.