| 摘要 |
PURPOSE:To obtain the picture discrimination device able to discriminate chromatic/achromatic color with high accuracy at a low cost by providing a comparator means comparing a difference signal outputted from a detection means with a preset value to the discrimination device. CONSTITUTION:Nonlinearization processing is applied to inputted RGB luminance signals by lookup tables LUT1-3. A difference signal circuit 4 detects a maximum value and a minimum value of R', G', B' signals outputted from the LUT1-3 and outputs a difference signal. A discrimination circuit 5 compares the difference signal S with a predetermined threshold level SO to output the result of discrimination of chromatic/achromatic color. That is, the discrimination circuit 5 outputs a level 1 representing a chromatic color in the case of S>SO and outputs a level 0 representing an achromatic color in the case of S<=SO. Since the discrimination for the chromatic/achromatic color based on the level of the difference signal after the RGB signals are subject to nonlinearization processing respectively, the accuracy of discrimination is high at a low cost for the discrimination of the chromatic/achromatic color. The device is eminent in the discrimination of a dark blue color especially. |
