Patent ID: 6298161
Filing Date: 2001-10-02
Classification: G06T

Abstract:
A digital image decoding apparatus having a function of suppressing blocking effects, comprising:input means for receiving image data coded in accordance with a coding method adopting a discrete cosine transform (DCT);decoding means for performing an inverted discrete cosine transform (IDCT) for the coded image data from the input means to decode original image; andfiltering means, responsive to a pixel clock and synchronous signals, for selectively filtering the decoded image data from the decoding means to eliminate blocking picture components, wherein said filtering means comprises,a first low pass filter for making a low pass filtering of the decoded image data from the decoding means in the horizontal axis,a second low pass filter for making a low pass filtering of the decoded image data from the decoding means in the vertical axis, andswitching means, responsive to the pixel clock and the synchronous signals, for selectively delivering image data from the first and second low pass filters and the decoded image data from the decoding means, wherein said switching means comprises:a first difference component detector for detecting difference components between the decoded image data from the decoding means and the data to be displayed using adjacent pixels in the horizontal axis; anda second difference component detector for detecting difference components between the decoded image data from the decoding means and the data to be displayed using adjacent pixels in the vertical axis; anda selector that responds to output signals of the first and second difference component detectors and selects any one of the decoded image data from the decoding means and the image data from the first and second low pass filters.