Autogressive pixel prediction in the neighborhood of image borders

A method for decoding digital image data that is coded, the method comprising:

• reconstructing prediction errors from the coded digital image data, the coded digital image data comprising one or more arrays of pixels with corresponding pixel values;
• predicting pixel values of the pixels to be decoded in each array by a prediction in which a predicted value of a current pixel is determined based on a weighted sum of reconstructed pixel values of reconstructed, previously decoded pixels in a specific neighborhood region adjacent to the current pixel;
• determining weights of the weighted sum based on linear, non-linear, or linear and non-linear equations for reconstructed pixels in a specific training region adjacent to the current pixel;
• and
• correcting the predicted pixel value by a reconstructed prediction error, resulting in a decoded pixel value for the current pixel,
• wherein the specific neighborhood region and the specific training region for the current pixel are determined as follows:
• determining pixels in a preset neighborhood region adjacent to the current pixel for which reconstructed pixel values exist, resulting in a modified neighborhood region defined by the determined pixels;
• determining pixels in a preset training region adjacent to the current pixel for which reconstructed pixel values exist and for which the modified neighborhood region exclusively includes pixels for which reconstructed pixel values exist, resulting in a modified training region defined by the determined pixels;
• determining a validation value being dependent on a parameter that increases in dependency on an increasing number of pixels in the modified training region and increases in dependency on a decreasing number of pixels in the modified neighborhood region;
• performing an iteration when the validation value corresponds to a parameter less than or less than or equal to a predetermined threshold value, wherein otherwise the specific neighborhood region corresponds to the modified neighborhood region, and the specific training region corresponds to the modified training region;
• removing, when the iteration is performed, at least one additional pixel in each iteration from the modified neighborhood region, resulting in an updated modified neighborhood region in each iteration, wherein the iteration terminates when the validation value determined in the corresponding iteration based on the number of pixels in the updated modified neighborhood region corresponds to a parameter exceeding or reaching the predetermined threshold value, the specific neighborhood region being the updated modified neighborhood region at the termination of the iteration and the specific training region being a region exclusively comprising pixels of the preset training region for which reconstructed pixel values exist and for which the updated modified neighborhood region at the termination of the iteration exclusively includes pixels for which reconstructed pixel values exist.

A method for coding and decoding digital image data, the method comprising:

• coding the digital image data, the digital image data comprising one or more arrays of pixels with corresponding pixel values, the coding comprising:
• predicting the pixel values of the pixels to be coded in each array by a prediction in which the predicted value of a current pixel is determined based on a weighted sum of reconstructed pixel values of reconstructed, previously processed pixels in a specific neighborhood region adjacent to the current pixel;
• determining weights of the weighted sum based on linear, non-linear, or linear and non-linear equations for reconstructed pixels in a specific training region adjacent to the current pixel;
• and
• processing a prediction error between predicted pixel values and original pixel values for generating coded image data, wherein determining the specific neighborhood region and the specific training region for the current pixel comprises:
• determining pixels in a preset neighborhood region adjacent to the current pixel for which reconstructed pixel values exist, resulting in a modified neighborhood region defined by the determined pixels;
• determining pixels in a preset training region adjacent to the current pixel for which reconstructed pixel values exist and for which the modified neighborhood region exclusively includes pixels for which reconstructed pixel values exist, resulting in a modified training region defined by the determined pixels;
• determining a validation value dependent on a parameter that increases in dependency on an increasing number of pixels in the modified training region and that increases in dependency on a decreasing number of pixels in the modified neighborhood region;
• performing an iteration when the validation value corresponds to a parameter less than or equal to a predetermined threshold value, and otherwise, the specific neighborhood region corresponds to the modified neighborhood region, and the specific training region corresponds to the modified training region;
• when the iteration is performed, removing, in each iteration, at least one additional pixel from the modified neighborhood region, resulting in an updated modified neighborhood region in each iteration, wherein the iteration terminates when the validation value determined in the corresponding iteration based on the number of pixels in the updated modified neighborhood region corresponds to a parameter exceeding or reaching the predetermined threshold value, the specific neighborhood region being the updated modified neighborhood region at the termination of the iteration and the specific training region being a region exclusively comprising pixels of the preset training region for which reconstructed pixel values exist and for which the updated modified neighborhood region at the termination of the iteration exclusively includes pixels for which reconstructed pixel values exist;
• and
• decoding the coded digital image data, the decoding comprising:
• reconstructing the prediction errors from the coded digital image data;
• predicting the pixel values of the pixels to be decoded in each array by a prediction in which the predicted value of the current pixel is determined based on the weighted sum of reconstructed pixel values of reconstructed, previously decoded pixels in the specific neighborhood region adjacent to the current pixel;
• determining the weights of the weighted sum based on linear, non-linear, or linear and non-linear equations for reconstructed pixels in the specific training region adjacent to the current pixel;
• and
• correcting the predicted pixel value by the reconstructed prediction error, resulting in a decoded pixel value for the current pixel.

An apparatus for coding digital image data, the digital image data comprising one or more arrays of pixels with corresponding pixel values, the apparatus comprising:

• a predictor configured to:
• predict the pixel values of the pixels to be coded in each array by a prediction in which the predicted value of a current pixel is determined based on a weighted sum of reconstructed pixel values of reconstructed, previously processed pixels in a specific neighborhood region adjacent to the current pixel;
• and
• determine weights of the weighted sum based on linear, non-linear, or linear and non-linear equations for reconstructed pixels in a specific training region adjacent to the current pixel;
• and
• a processor configured to:
• process a prediction error between predicted pixel values and original pixel values for generating the coded image data;
• determine the specific neighborhood region and the specific training region for the current pixel, the determination of the specific neighborhood region and the specific training region comprising:
• determination of the pixels in a preset neighborhood region adjacent to the current pixel for which reconstructed pixel values exist, resulting in a modified neighborhood region defined by the determined pixels;
• determination of pixels in a preset training region adjacent to the current pixel for which reconstructed pixel values exist and for which the modified neighborhood region exclusively includes pixels for which reconstructed pixel values exist, resulting in a modified training region defined by the determined pixels;
• determination of a validation value being dependent on a parameter that increases in dependency on an increasing number of pixels in the modified training region and increases in dependency on a decreasing number of pixels in the modified neighborhood region;
• performance of an iteration when the validation value corresponds to a parameter less than or less than or equal to a predetermined threshold value, and otherwise, the specific neighborhood region corresponds to the modified neighborhood region, and the specific training region corresponds to the modified training region;
• removal, when the iteration is performed, of at least one additional pixel in each iteration from the modified neighborhood region, resulting in an updated modified neighborhood region in each iteration, wherein the iteration terminates when the validation value determined in the corresponding iteration based on the number of pixels in the updated modified neighborhood region corresponds to a parameter exceeding or reaching the predetermined threshold value, the specific neighborhood region being the updated modified neighborhood region at the termination of the iteration and the specific training region being a region exclusively comprising pixels of the preset training region for which reconstructed pixel values exist and for which the updated modified neighborhood region at the termination of the iteration exclusively includes pixels for which reconstructed pixel values exist.

An apparatus for decoding digital image data that is coded, the apparatus comprising:

• a processor configured to:
• reconstruct prediction errors from the coded digital image data, the digital image data comprising one or more arrays of pixels with corresponding pixel values;
• predict pixel values of pixels to be decoded in each array of the one or more arrays of pixels by a prediction in which the predicted value of a current pixel is determined based on a weighted sum of reconstructed pixel values of reconstructed, previously decoded pixels in a specific neighborhood region adjacent to the current pixel, wherein weights of the weighted sum are determined based on linear, non-linear, or linear and non-linear equations for reconstructed pixels in a specific training region adjacent to the current pixel;
• correct the predicted pixel value by the reconstructed prediction error, resulting in a decoded pixel value for the current pixel;
• and
• determine the specific neighborhood region and the specific training region for the current pixel, the determination of the specific neighborhood region and the specific training region comprising:
• determination of pixels in a preset neighborhood region adjacent to the current pixel for which reconstructed pixel values exist, resulting in a modified neighborhood region defined by the determined pixels;
• determination of pixels in a preset training region adjacent to the current pixel for which reconstructed pixel values exist and for which the modified neighborhood region exclusively includes pixels for which reconstructed pixel values exist, resulting in a modified training region defined by the determined pixels;
• determination of a validation value dependent on a parameter that increases in dependency on an increasing number of pixels in the modified training region and increases in dependency on a decreasing number of pixels in the modified neighborhood region;
• performance of an iteration when the validation value corresponds to a parameter less than or less than or equal to a predetermined threshold value, otherwise the specific neighborhood region corresponding to the modified neighborhood region and the specific training region corresponding to the modified training region;
• when the iteration is performed, removal of at least one additional pixel in each iteration step from the modified neighborhood region, resulting in an updated modified neighborhood region in each iteration step, wherein the iteration terminates when the validation value determined in the corresponding iteration step based on the number of pixels in the updated modified neighborhood region corresponds to a parameter exceeding or reaching the predetermined threshold value, the specific neighborhood region being the updated modified neighborhood region at the termination of the iteration and the specific training region being a region exclusively comprising pixels of the preset training region for which reconstructed pixel values exist and for which the updated modified neighborhood region at the termination of the iteration exclusively includes pixels for which reconstructed pixel values exist.

A codec for coding and decoding digital image data, the codec comprising:

• a coding apparatus for coding digital image data, the digital image data comprising one or more arrays of pixels with corresponding pixel values, the coding apparatus comprising:
• a predictor configured to:
• predict the pixel values of the pixels to be coded in each array by a prediction in which the predicted value of a current pixel is determined based on a weighted sum of reconstructed pixel values of reconstructed, previously processed pixels in a specific neighborhood region adjacent to the current pixel;
• and
• determine weights of the weighted sum based on linear, non-linear, or linear and non-linear equations for reconstructed pixels in a specific training region adjacent to the current pixel;
• and
• a processor configured to:
• process a prediction error between predicted pixel values and original pixel values for generating the coded image data;
• determine the specific neighborhood region and the specific training region for the current pixel, the determination of the specific neighborhood region and the specific training region comprising:
• determination of the pixels in a preset neighborhood region adjacent to the current pixel for which reconstructed pixel values exist, resulting in a modified neighborhood region defined by the determined pixels;
• determination of pixels in a preset training region adjacent to the current pixel for which reconstructed pixel values exist and for which the modified neighborhood region exclusively includes pixels for which reconstructed pixel values exist, resulting in a modified training region defined by the determined pixels;
• determination of a validation value being dependent on a parameter that increases in dependency on an increasing number of pixels in the modified training region and increases in dependency on a decreasing number of pixels in the modified neighborhood region;
• performance of an iteration when the validation value corresponds to a parameter less than or less than or equal to a predetermined threshold value, and otherwise, the specific neighborhood region corresponds to the modified neighborhood region, and the specific training region corresponds to the modified training region;
• removal, when the iteration is performed, of at least one additional pixel in each iteration from the modified neighborhood region, resulting in an updated modified neighborhood region in each iteration, wherein the iteration terminates when the validation value determined in the corresponding iteration based on the number of pixels in the updated modified neighborhood region corresponds to a parameter exceeding or reaching the predetermined threshold value, the specific neighborhood region being the updated modified neighborhood region at the termination of the iteration and the specific training region being a region exclusively comprising pixels of the preset training region for which reconstructed pixel values exist and for which the updated modified neighborhood region at the termination of the iteration exclusively includes pixels for which reconstructed pixel values exist;
• and
• a decoding apparatus for decoding digital image data that is coded, the decoding apparatus comprising:
• the processor configured to:
• reconstruct prediction errors from the coded digital image data, the digital image data comprising one or more arrays of pixels with corresponding pixel values;
• predict pixel values of pixels to be decoded in each array of the one or more arrays of pixels by a prediction in which the predicted value of a current pixel is determined based on a weighted sum of reconstructed pixel values of reconstructed, previously decoded pixels in a specific neighborhood region adjacent to the current pixel, wherein weights of the weighted sum are determined based on linear, non-linear, or linear and non-linear equations for reconstructed pixels in a specific training region adjacent to the current pixel;
• correct the predicted pixel value by the reconstructed prediction error, resulting in a decoded pixel value for the current pixel;
• and
• determine the specific neighborhood region and the specific training region for the current pixel, the determination of the specific neighborhood region and the specific training region comprising:
• determination of pixels in a preset neighborhood region adjacent to the current pixel for which reconstructed pixel values exist, resulting in a modified neighborhood region defined by the determined pixels;
• determination of pixels in a preset training region adjacent to the current pixel for which reconstructed pixel values exist and for which the modified neighborhood region exclusively includes pixels for which reconstructed pixel values exist, resulting in a modified training region defined by the determined pixels;
• determination of a validation value dependent on a parameter that increases in dependency on an increasing number of pixels in the modified training region and increases in dependency on a decreasing number of pixels in the modified neighborhood region;
• performance of an iteration when the validation value corresponds to a parameter less than or less than or equal to a predetermined threshold value, otherwise the specific neighborhood region corresponding to the modified neighborhood region and the specific training region corresponding to the modified training region;
• when the iteration is performed, removal of at least one additional pixel in each iteration step from the modified neighborhood region, resulting in an updated modified neighborhood region in each iteration step, wherein the iteration terminates when the validation value determined in the corresponding iteration step based on the number of pixels in the updated modified neighborhood region corresponds to a parameter exceeding or reaching the predetermined threshold value, the specific neighborhood region being the updated modified neighborhood region at the termination of the iteration and the specific training region being a region exclusively comprising pixels of the preset training region for which reconstructed pixel values exist and for which the updated modified neighborhood region at the termination of the iteration exclusively includes pixels for which reconstructed pixel values exist.