Image size transformation method for orthogonal transformation coded image

An image size transformation method for an orthogonal transformation coded image, enlarging an image size to output a decoded image, in respect with an image compressing and coding using an orthogonal transformation, comprising the steps of:

• reading out orthogonal transformation coefficients being coded by an N point orthogonal transformation, where N is a natural number;
• conducting a coefficient transformation by an operation process on the orthogonal transformation coefficients to obtain orthogonal transformation coefficients, after having the image size enlarged by a certain integer;
• and
• decoding the transformation coefficients by an N point inverse orthogonal transformation so as to output an enlarged image, thus executing enlargement and decoding of a coded image.

An image size transformation method for an orthogonal transformation coded image, coding an image into hierarchies to obtain a plurality of decoded images with different sizes, comprising a coding stage and a decoding stage:

• the coding stage including the steps of;
• provided that an input image is being previously hierarchically organized according to different sizes, conducting an orthogonal transformation with respect to each hierarchy to obtain orthogonal transformation coefficients,
• coding the orthogonal transformation coefficient of the lowest hierarchy with the smallest image size such that it should be outputted as coded data,
• obtaining difference data between orthogonal transformation coefficients of a subject hierarchy and orthogonal transformation coefficients of the other lower hierarchies with smaller image sizes having been enlarged on the coefficients, and
• coding the obtained difference data such that it should be outputted as coded data,
• the decoding stage including the steps of;
• conducting an inverse coding process on the coded data to obtain difference data between orthogonal transformation coefficients of the lowest hierarchy and orthogonal transformation coefficients of the other hierarchies,
• adding together the difference data of the subject hierarchy and the orthogonal transformation coefficients of the other lower hierarchies except for the lowest having been enlarged by an enlargement process on the coefficients, so as to consecutively obtain through a calculation process orthogonal transformation coefficients for each hierarchy starting from the lower hierarchies, and
• conducting an inverse orthogonal transformation on the obtained orthogonal transformation coefficients of each hierarchy to finally restore and output hierarchically decoded images.

An image size transformation method for an orthogonal transformation coded image, reducing an image size to output a decoded image, in respect with an image compressing and coding using an orthogonal transformation, comprising the steps of:

• reading out orthogonal transformation coefficients being coded by an N point orthogonal transformation, where N is a natural number;
• conducting a coefficient transformation by an operation process on the orthogonal transformation coefficients to obtain orthogonal transformation coefficients, after having the image size reduced;
• and
• decoding the transformation coefficients by an N point inverse orthogonal transformation so as to output a reduced image, thus obtaining a reduced decoded image of a coded image.

An image size transformation method for an orthogonal transformation coded image, coding an image into hierarchies to obtain a plurality of decoded images with different sizes, comprising a coding stage and a decoding stage:

• the coding stage including the steps of;
• conducting an N point orthogonal transformation on an input image to obtain orthogonal transformation coefficients,
• conducting a hierarchical reduction process on the obtained orthogonal transformation coefficients to obtain data of N point orthogonal coefficients constructed in a plurality of hierarchies of different image sizes,
• coding the orthogonal transformation coefficients of the lowest hierarchy with the smallest image size such that it should be outputted as coded data,
• obtaining difference data between orthogonal transformation coefficients of a subject hierarchy and orthogonal transformation coefficients of the other lower hierarchies with smaller image sizes having been enlarged on the coefficients, and
• coding the obtained difference data such that it should be outputted as coded data,
• the decoding stage including the steps of;
• conducting an N point inverse coding process on the coded data to obtain difference data between orthogonal transformation coefficients of the lowest hierarchy and orthogonal transformation coefficients of the other hierarchies,
• adding together the difference data of the subject hierarchy and the orthogonal transformation coefficients of the other lower hierarchies except for the lowest having been enlarged by an enlargement process on the coefficients, so as to obtain through a calculation process orthogonal transformation coefficients for each hierarchy, and
• conducting an N point inverse orthogonal transformation on the obtained orthogonal transformation coefficients of each hierarchy to finally restore and output hierarchically decoded images.