Patent ID: 6385249
Filing Date: 2002-05-07
Classification: G06T,H04N

Abstract:
A picture data converting apparatus for converting first picture data into second picture data whose quality is lower than the first picture data, comprising:an intermediate picture data generating portion for generating intermediate picture data whose quality is almost the same as the second picture data with the first picture data; a storing portion for storing the intermediate picture data; a predictive picture data generating portion for generating predictive picture data whose quality is almost the same as the first picture data according to the intermediate picture data stored in said storing portion and predictive coefficients; an error detecting portion for detecting an error between the first picture data and the predictive picture data; a first determining portion for determining whether or not a variation amount of the error detected by said error detecting portion is equal to or larger than a first threshold value; a second determining portion for determining whether or not the error detected by said error detecting portion is equal to or larger than a second threshold value; and an adjusting portion for performing a first adjusting process for pixel values of the intermediate picture data stored in said storing portion based on the first input picture data when the variation amount of the error is equal to or larger than the first threshold value as the determined result of said first determining portion, for performing a second adjusting process for a pixel value of the intermediate picture data stored in said storing portion with a non-linear variation amount when the variation amount of the error is smaller than the first threshold value as the determined result of said first determining portion and when the error is equal to or larger than the second threshold value as the determined result of said second determining portion, and for determining the intermediate picture data stored in said storing portion as the second picture data when the error is smaller than the second threshold value as the determined result of said second determining portion.