Patent attributes
An image data converting apparatus comprising an MPEG2-image data decoding section 19, a scan-converting section 20, an MPEG4-image encoding section 21, and a picture-type determining section 18. The MPEG2-image data decoding section 19 decodes input MPEG2-image compressed data in both the vertical direction and the horizontal direction by using only lower, fourth-order coefficients. The scan-converting section 20 converts interlaced-scan pixel data to sequential-scan pixel data. The MPEG4-image encoding section 21 generates MPEG4-image compressed data from the sequential-scan pixel signals. The sections 19, 20 and 21 are connected in series. The picture-type determining section 18 is connected to the input of the MPEG2-image data decoding section 19. The section 18 determines the picture type of each frame data contained in the interlaced-scan MPEG4-picture compressed data, outputs only the frame data about I/P pictures, discards the frame data about B pictures, thereby converting the frame rate.
