| 摘要 |
<p>PURPOSE:To prevent the visual deterioration in picture quality owing to the difference of the quality caused by the difference of a mode by calculating interpolating error from a picture signal, making it as original interpolating error, correcting a part of the original interpolating error or the whole interpolating error with the aid of past original interpolating error or a past mode, making the result of the correction as corrected interpolating error and deciding the mode with the aid of the corrected interpolating error. CONSTITUTION:When the picture signal is inputted, the original interpolating error S for the mode 2 of each block is calculated. Then, a some fixed value alpha is added to the original interpolating picture element of the block which is the mode 1 at one before field and made the corrected interpolating error S' for each block. A histogram about the corrected interpolating error is produced and the content of it is read from it's bigger corrected interpolating error and added to the value alpha. Then, the value of the corrected interpolating error S' when more than one-third of the whole blocks are read is made to be a threshold value (Th). The whole blocks are assigned to the mode 2 or the mode 1 according as it's corrected interpolating error S' is over or below the threshold value (Th) and outputted. Thus the variation of the mode being the cause of deterioration in the image quality can be controlled.</p> |
