Method and device for determining a data configuration of a digital signal of an image

A method of determining a data configuration of a digital signal of an image, the signal having undergone at least one spatio-temporal transformation in at least one resolution level, thus providing transformed coefficients each taking the form of a series of binary elements comprising a plurality of portions, characterized in that the method comprises the following steps:

• i) determining at least one minimum rate reduction (Dmin) with respect to the total data rate of at least one resolution level of the signal, as a function of a quality mode desired for the signal,
• ii) determining, for a given resolution level (R=Ri) and for at least certain transformed coefficients of that level, a number m which may vary from one coefficient to another, of portions of binary elements to delete from the signal, with m≦N, where N is a maximum given number which guarantees a given visual quality in the resolution level considered,
• iii) determining the reduction in rate (Di) generated by the deletion in the resolution level (R) of the m portions of binary elements of said at least certain transformed coefficients,
• iv) comparing the rate reduction added to the possible rate reduction determined for the resolution level hierarchically above with respect to the minimum rate reduction (Dmin),
• v) as a function of the result of the comparison, deciding as to the reiteration of steps ii) to v) for the resolution level R or for the resolution level below (R=Ri-1) or as to the determined data configuration.

A method of determining a data configuration of a digital signal of an image, the signal having undergone at least one spatio-temporal transformation in at least one resolution level, thus providing transformed coefficients each taking the form of a series of binary elements comprising a plurality of portions, characterized in that the method comprises the following steps:

• i) determining at least one minimum rate reduction (Dmin) with respect to the total rate of a display resolution level Ra as a function of a quality mode desired for the signal,
• ii) determining, for a resolution level Ri which corresponds initially to Ra and for at least certain transformed coefficients of that level, a number m which may vary from one coefficient to another, of portions of binary elements to delete from the signal, with m≦N, where N is a maximum given number which guarantees a given visual quality in the resolution level considered,
• iii) determining the reduction in rate (Di) generated by the deletion in the resolution level (Ri) of the m portions of binary elements of said at least certain transformed coefficients,
• iv) comparing the reduction in rate with respect to the minimum rate reduction (Dmin),
• v) as a function of the result of the comparison, deciding as to the reiteration of steps ii) to v) for the resolution level (Ri) or for the resolution level hierarchically below (Ri=Ri−1) or as to the reiteration of steps i) to v) for the level of display resolution hierarchically below (Ra=Ra−1) or as to the determined data configuration.

A device for determining a data configuration of a digital signal of an image, the signal having undergone at least one spatio-temporal transformation in at least one resolution level, thus providing transformed coefficients each taking the form of a series of binary elements comprising a plurality of portions, characterized in that the device comprises:

• means for determining at least one minimum rate reduction (Dmin) with respect to the total rate of data of at least one resolution level of the signal, as a function of a quality mode desired for the signal,
• means for determining, for a given resolution level (R=Ri) and for at least certain transformed coefficients of that level, a number m, which may vary from one coefficient to another, of portions of binary elements to delete from the signal, with m≦N, where N is a maximum given number which guarantees a given visual quality in the resolution level considered,
• means for determining the reduction in rate (Di) generated by the deletion in the resolution level (R) of the m portions of binary elements of said at least certain transformed coefficients,
• means for comparing the rate reduction added to the possible rate reduction determined for the resolution level hierarchically above with respect to the minimum rate reduction (Dmin),
• means for deciding as to the determined configuration of data, as a function of the result of the comparison.

A device for determining a data configuration of a digital signal of an image, the signal having undergone at least one spatio-temporal transformation in at least one resolution level, characterized in that the device comprises:

• means for determining at least one minimum rate reduction (Dmin) with respect to the total rate of a display resolution level Ra as a function of a quality mode desired for the signal,
• means for determining, for a resolution level Ri which corresponds initially to Ra and for at least certain transformed coefficients of that level, a number m which may vary from one coefficient to another, of portions of binary elements to delete from the signal, with m≦N, where N is a maximum given number which guarantees a given visual quality in the resolution level considered,
• means for determining the reduction in rate (Di) generated by the deletion in the resolution level (Ri) of the m portions of binary elements of said at least certain transformed coefficients,
• means for comparing the reduction in rate with respect to the minimum rate reduction (Dmin),
• means for deciding as to the configuration of the data as a function of the result of the comparison.