JP2004166254A5 - - Google Patents

Claims (19)

Filtering means for generating a subband by applying a low-pass filter and a high-pass filter to an input image in a vertical direction and a horizontal direction, and performing a hierarchical filtering process on the subband of the low-frequency component;
Code block generation means for dividing the subband generated by the filtering means and generating a code block of a predetermined size;
Bit plane generating means for generating a bit plane from the most significant bit to the least significant bit in the code block unit;
A coded prediction means for generating a coded number information to predict the number of coded to be coded,
Of the generated the coded by the encoding target prediction unit, from the most significant bit side of each code block for encoding target given by the encoding target number information only, and encoding means for encoding An image encoding apparatus comprising: 2. The image encoding apparatus according to claim 1, wherein the number of encoding targets is the number of bit planes or the number of encoding passes to be encoded. The encoding target prediction unit counts the number of effective bit planes excluding zero bit planes for all code blocks in the frame of the input image, and refers to a predetermined table based on the count result, thereby image encoding apparatus according to claim 1, wherein the obtaining the number of coded as a the encoding target. 4. The image encoding apparatus according to claim 3 , wherein the predetermined table is a table in which a range of effective bit planes and the number of encoding targets to be encoded are associated with each other. The encoding target prediction unit counts the number of effective bit planes excluding zero bit planes for all code blocks in the subband of the input image, and refers to a predetermined table based on the count result, 2. The image encoding apparatus according to claim 1, wherein the number of encoding targets to be encoded is obtained for each band. 6. The image encoding apparatus according to claim 5 , wherein the predetermined table is a table in which a range of effective bit planes and the number of encoding targets to be encoded are associated with each other for each subband. When the input image is an interlaced image, the number of objects to be encoded corresponding to a subband having a highest division level in which the horizontal direction is low and the vertical direction is high is set to 0. The image encoding device according to claim 6 . When the input image is an interlaced image, the number of encoding targets corresponding to all sub-level subbands whose horizontal direction is a low frequency and whose vertical direction is a high frequency is set to 0. Item 7. The image encoding device according to Item 6 . All of the order of arithmetic coding of the least significant bits from a high arithmetic code most bit position code block of the input image, the when adding the calculated code for each of the bit plane, exceeds a predetermined target code amount The image coding apparatus according to claim 1 , further comprising code amount control means for stopping addition of the calculated code . 10. The image coding apparatus according to claim 9 , wherein the code amount control means adds the arithmetic codes in the order of the lowest band to the highest band for the arithmetic codes at the same bit position. 10. The image coding apparatus according to claim 9 , wherein the code amount control means adds the arithmetic codes in the order of luminance information components to color difference information components for arithmetic codes at the same bit position. The transform coefficients in a subband generated by said filtering means, further Ru comprising a quantizing means for quantizing by dividing a quantization step size by weighting using a weighting coefficient set for each of the sub-band The image coding apparatus according to claim 1 . 13. The image coding apparatus according to claim 12 , wherein the weighting coefficient is set so that the quantization step size becomes smaller as a subband of a low frequency component. 13. The image coding apparatus according to claim 12 , wherein the weighting factor is set so that the quantization step size is smaller in the luminance information component than in the color difference information component. 13. The image coding apparatus according to claim 12 , wherein the code amount control means adds the arithmetic codes in the order of the lowest band to the highest band for the arithmetic codes at the same bit position. 13. The image encoding apparatus according to claim 12 , wherein the code amount control means adds the arithmetic codes in the order of luminance information components to color difference information components for arithmetic codes at the same bit position. A filtering step of applying a low-pass filter and a high-pass filter to the input image in a vertical direction and a horizontal direction to generate subbands, and hierarchically filtering the subbands of the low-frequency components;
A code block generation step of dividing the subband generated in the filtering step and generating a code block of a predetermined size;
A bit plane generating step for generating a bit plane from the most significant bit to the least significant bit in the code block unit;
A coded prediction step of generating a coded number information to predict the number of coded to be coded,
The coded prediction process of the coding target generated by, for only the coded number given from the most significant bit in the coded number information of each code block, coding for coding An image encoding method comprising the steps of: In a program for causing a computer to execute a predetermined process,
A filtering step of applying a low-pass filter and a high-pass filter to the input image in a vertical direction and a horizontal direction to generate subbands, and hierarchically filtering the subbands of the low-frequency components;
A code block generation step of dividing the subband generated in the filtering step and generating a code block of a predetermined size;
A bit plane generating step for generating a bit plane from the most significant bit to the least significant bit in the code block unit;
A coded prediction step of generating a coded number information to predict the number of coded to be coded,
Among the encoding target generated by the coded prediction step, the coded number from the most significant bit side is given by the coding target number information of each code block only encoding step of encoding A program characterized by having and. In a computer-readable recording medium on which a program for causing a computer to execute predetermined processing is recorded,
A filtering step of applying a low-pass filter and a high-pass filter to the input image in a vertical direction and a horizontal direction to generate subbands, and hierarchically filtering the subbands of the low-frequency components;
A code block generation step of dividing the subband generated in the filtering step and generating a code block of a predetermined size;
A bit plane generating step for generating a bit plane from the most significant bit to the least significant bit in the code block unit;
A coded prediction step of generating a coded number information to predict the number of coded to be coded,
Among the encoding target generated by the coded prediction step, the coded number from the most significant bit side is given by the coding target number information of each code block only encoding step of encoding A recording medium on which a program is recorded.