Image encoding apparatus and method, program, and storage medium

An image encoding method for compression-encoding image data, comprising:

• the first compression-encoding step of compression-encoding image data using a first compression-encoding parameter, which can be changed, and generating a compression-encoded encoded data stream;
• the second compression-encoding step of compression-encoding image data using a second compression-encoding parameter which is generated in accordance with the first compression-encoding parameter applied to the first compression-encoding step, and of generating an encoded data stream of a substitution candidate, which is compression-encoded at a higher compression ratio;
• the re-compression-encoding step of re-compression-encoding the encoded data stream of the substitution candidate, which is compression-encoded in the second compression-encoding step, and an encoded data stream of a substitution candidate, which was compression-encoded by itself previously, using the second compression-encoding parameter applied to the second compression-encoding step, and of generating an encoded data stream of a substitution candidate, which is compression-encoded at a higher compression ratio;
• the data size determination step of counting a data size of an encoded data stream, which is compression-encoded in the first compression-encoding step, and determining if the data size is not less than a predetermined size;
• the change step of replacing, when it is determined in the data size determination step that the data size of the encoded data stream compression-encoded in the first compression-encoding step is not less than the predetermined size, the first compression-encoding parameter by the second compression-encoding parameter;
• the save step of saving, when it is determined in the data size determination step that the data size of the encoded data stream compression-encoded in the first compression-encoding step is not less than the predetermined size, the encoded data streams of the substitution candidates, which were previously compression-encoded in the second compression-encoding step and the re-compression-encoding step, as an encoded data stream compression-encoded in the first compression-encoding step after the first encoding parameter is changed, and of saving the encoded data stream, which is compression-encoded in the first compression-encoding step after the first compression-encoding parameter is changed, as a subsequent encoded data stream;
• the process execution selection step of selecting, when it is determined in the data size determination step that the data size of the encoded data stream compression-encoded in the first compression-encoding step is not less than the predetermined size, if a compression-encoding process in the second compression-encoding step and a re-compression-encoding process in the re-compression-encoding step are to be executed;
• and
• update step of updating, when it is selected in the process execution selection step selects that the compression-encoding process in the second compression-encoding step and the re-compression-encoding process in the re-compression-encoding step are to be executed, the second compression-encoding parameter to be applied to the second compression-encoding step and the re-compression-encoding step to a new compression-encoding parameter, which can compress data at a higher compression ratio.

An image encoding apparatus for compression-encoding image data, comprising:

• first compression-encoding means for compression-encoding image data using a first compression-encoding parameter, which can be changed, and generating a compression-encoded encoded data stream;
• re-compression-encoding means for re-compression-encoding the encoded data stream compression-encoded by said first compression-encoding means and an encoded data stream of a substitution candidate, which was compression-encoded by itself previously, using a second compression-encoding parameter which is generated in accordance with the first compression-encoding parameter applied to said first compression-encoding means, and for generating an encoded data stream of a substitution candidate, which is compression-encoded at a higher compression ratio;
• data size determination means for counting a data size of an encoded data stream, which is compression-encoded by said first compression-encoding means, and determining if the data size is not less than a predetermined size;
• change means for, when said data size determination means determines that the data size of the encoded data stream compression-encoded by said first compression-encoding means is not less than the predetermined size, replacing the first compression-encoding parameter by the second compression-encoding parameter;
• save means for, when said data size determination means determines that the data size of the encoded data stream compression-encoded by said first compression-encoding means is not less than the predetermined size, saving the encoded data stream of the substitution candidate, which was previously compression-encoded by said re-compression-encoding means, as an encoded data stream compression-encoded by said first compression-encoding means after the first encoding parameter is changed, and for saving the encoded data stream, which is compression-encoded by said first compression-encoding means after the first compression-encoding parameter is changed, as a subsequent encoded data stream;
• process execution selection means for, when said data size determination means determines that the data size of the encoded data stream compression-encoded by said first compression-encoding means is not less than the predetermined size, selecting if are-compression-encoding process by said re-compression-encoding means is to be executed;
• and
• update means for, when said process execution selection means selects that the re-compression-encoding process by said re-compression-encoding means is to be executed, updating the second compression-encoding parameter to be applied to said re-compression-encoding means to a new compression-encoding parameter, which can compress data at a higher compression ratio.

An image encoding apparatus for compression-encoding image data, comprising:

• first compression-encoding means for compression-encoding image data using a first compression-encoding parameter, which can be changed, and generating a compression-encoded encoded data stream;
• second compression-encoding means for compression-encoding image data using a second compression-encoding parameter which is generated in accordance with the first compression-encoding parameter applied to said first compression-encoding means, and for generating an encoded data stream of a substitution candidate, which is compression-encoded at a higher compression ratio;
• re-compression-encoding means for re-compression-encoding the encoded data stream of the substitution candidate, which is compression-encoded by said second compression-encoding means, and an encoded data stream of a substitution candidate, which was compression-encoded by itself previously, using the second compression-encoding parameter applied to said second compression-encoding means, and for generating an encoded data stream of a substitution candidate, which is compression-encoded at a higher compression ratio;
• data size determination means for counting a data size of an encoded data stream, which is compression-encoded by said first compression-encoding means, and determining if the data size is not less than a predetermined size;
• change means for, when said data size determination means determines that the data size of the encoded data stream compression-encoded by said first compression-encoding means is not less than the predetermined size, replacing the first compression-encoding parameter by the second compression-encoding parameter;
• save means for, when said data size determination means determines that the data size of the encoded data stream compression-encoded by said first compression-encoding means is not less than the predetermined size, saving the encoded data streams of the substitution candidates, which were previously compression-encoded by said second compression-encoding means and said re-compression-encoding means, as an encoded data stream compression-encoded by said first compression-encoding means after the first encoding parameter is changed, and for saving the encoded data stream, which is compression-encoded by said first compression-encoding means after the first compression-encoding parameter is changed, as a subsequent encoded data stream;
• process execution selection means for, when said data size determination means determines that the data size of the encoded data stream compression-encoded by said first compression-encoding means is not less than the predetermined size, selecting if a compression-encoding process by said second compression-encoding means and a re-compression-encoding process by said re-compression-encoding means are to be executed;
• and
• update means for, when said process execution selection means selects that the compression-encoding process by said second compression-encoding means and the re-compression-encoding process by said re-compression-encoding means are to be executed, updating the second compression-encoding parameter to be applied to said second compression-encoding means and said re-compression-encoding means to a new compression-encoding parameter, which can compress data at a higher compression ratio.

An image encoding method of compression-encoding image data, comprising:

• the first compression-encoding step of compression-encoding image data using a first compression-encoding parameter, which can be changed;
• the second compression-encoding step of compression-encoding the compression-encoded results of the first compression-encoding step using a second compression-encoding parameter which can compress data at a higher compression ratio than the first compression-encoding parameter and can be changed;
• the determination step of counting a data size of an encoded data stream, which is compression-encoded in the first compression-encoding step, and determining if the data size is not less than a predetermined size;
• the change step of replacing, every time it is determined in the determination step that the data size of the encoded data stream obtained in the first compression-encoding step is not less than the predetermined size, the first compression-encoding parameter by the second compression-encoding parameter, and changing the second compression-encoding parameter to a parameter used to obtain a higher compression ratio;
• the save step of saving, when it is determined in the determination step that the data size of the encoded data stream obtained in the first compression-encoding step is not less than the predetermined size, an encoded data stream, which was previously compression-encoded in the second compression-encoding step, as encoded data stream compression-encoded in the first compression-encoding step after the parameter is changed;
• the re-compression-encoding step of re-compression-encoding, when it is determined in the determination step that the data size of the encoded data stream obtained in the first compression-encoding step is not less than the predetermined size, the encoded data stream, which was previously compression-encoded in the second compression-encoding step, using the second compression-encoding parameter, which is changed in the change step;
• and
• the control step of controlling, when it is determined or predicted in the determination step that the data size of the encoded data stream obtained in the first compression-encoding step is not less than the predetermined size before the re-compression-encoding process of the re-compression-encoding step is completed, the first compression-encoding step to abort a compression-encoding process.

An image encoding apparatus for compression-encoding image data, comprising:

• first compression-encoding means for compression-encoding image data using a first compression-encoding parameter, which can be changed;
• second compression-encoding means for compression-encoding the compression-encoded results of said first compression-encoding means using a second compression-encoding parameter which can compress data at a higher compression ratio than the first compression-encoding parameter and can be changed;
• determination means for counting a data size of an encoded data stream, which is compression-encoded by said first compression-encoding means, and determining if the data size is not less than a predetermined size;
• change means for, every time said determination means determines that the data size of the encoded data stream obtained by said first compression-encoding means is not less than the predetermined size, replacing the first compression-encoding parameter by the second compression-encoding parameter, and changing the second compression-encoding parameter to a parameter used to obtain a higher compression ratio;
• save means for, when said determination means determines that the data size of the encoded data stream obtained by said first compression-encoding means is not less than the predetermined size, saving an encoded data stream, which was previously compression-encoded by said second compression-encoding means, as encoded data stream compression-encoded by said first compression-encoding means after the parameter is changed;
• re-compression-encoding means for, when said determination means determines that the data size of the encoded data stream obtained by said first compression-encoding means is not less than the predetermined size, re-compression-encoding the encoded data stream, which was previously compression-encoded by said second compression-encoding means, using the second compression-encoding means parameter, which is changed by said change means;
• and
• control means for, when said determination means determines or predicts that the data size of the encoded data stream obtained by said first compression-encoding means is not less than the predetermined size before the re-compression-encoding process of said re-compression-encoding means is completed, controlling said first compression-encoding means to abort a compression-encoding process.