Abstract: An image processing apparatus includes a decoding circuit block decoding a coded image input signal specified by NTSC system with a frame rate of the NTSC system and writing a decoded image signal in an image memory as image data, and a display-image producing circuit block producing a display image data by reading the image data from the image memory with a frame rate specified by PAL system, thereby achieving the frame rate transformation from the NTSC system to PAL system, and at this time, carrying out the skipping for display at every one extent field.

Abstract: In a moving picture decoding control system, when the amount of codes accumulated in a buffer memory is between first and second thresholds, the reading-out of the buffer memory is stopped and an image memory is repeatedly read out just after the I-picture or the P-picture of one frame is decoded until the amount of codes accumulated in the buffer memory exceeds the second threshold. When the amount of codes accumulated in the buffer memory is smaller than the first threshold, the reading-out of the buffer memory is stopped and the image memory is repeatedly read out until the amount of codes accumulated in the buffer memory exceeds the second threshold.

Abstract: A quick image processor of reduced circuit scale for carrying out compression and expansion of image data, including a quantization-inverse quantization device which executes a quantization of the image data using quantization steps corresponding to frequency components and an inverse quantization of decoded data using the quantization steps. The quantization-inverse quantization device includes a first shifter for executing a predetermined bit number shift of input data, an add-subtract device for adding or subtracting the output of the first shifter to or from the input data, a look-up table device for multiplying the input data by a multiple previously stored therein, and a second shifter for executing a predetermined bit number shift of either the output of the add-subtract device or the output of the look-up table device, resulting in carrying out ready IC fabrication and improving approximation accuracy of the quantization steps.

Abstract: In a moving picture decoding control system, when the amount of codes accumulated in a buffer memory is between first and second thresholds, the reading-out of the buffer memory is stopped and an image memory is repeatedly read out just after the I-picture or the P-picture of one frame is decoded until the amount of codes accumulated in the buffer memory exceeds the second threshold. When the amount of codes accumulated in the buffer memory is smaller than the first threshold, the reading-out of the buffer memory is stopped and the image memory is repeatedly read out until the amount of codes accumulated in the buffer memory exceeds the second threshold.

Abstract: A picture signal processing system includes an orthogonal transformer which performs an orthogonal transformation upon a group of picture signals to generate transformed coefficients G. A quantizer divides each of the transformed coefficients G by a quantization factor C determined by ##EQU1## where A and B are integers, and S is a sign. The quantizer generates a quantization coefficient G/C for each of the transformed coefficients G. Then, an encoder encodes each of the quantization coefficients G/C to generate compressed signals of the picture signals.