Abstract: Disclosed are methods of allocating tasks for a print job in a multi-threaded system. One method determines a utilisation measure of at least one of a plurality of intermediate data generating threads, and a complexity limit of a intermediate data generation task. The complexity limit is decreased if the determined utilisation measure of the intermediate data generating thread is under a predetermined threshold. The complexity limit limits a processing load of the intermediate data generation task to be allocated to the intermediate data generating thread. The method then compares the processing load of the intermediate data generation task to be allocated with the determined complexity limit, and allocates the intermediate data generation task to the intermediate data generating thread for processing in an event that the processing load of the intermediate data generation task satisfies the complexity limit.

Abstract: A method of determining a thread from a plurality of threads to execute a task in a multi-processor computer system. The plurality of threads is grouped into at least one subset associated with a cache memory of the computer system. The task has a type determined by a set of instructions. The method obtains an execution history of the subset of plurality of threads and determines a weighting for each of the set of instructions and the set of data, the weightings depending on the type of the task. A suitability of the subset of the threads to execute the task based on the execution history and the determined weightings, is then determined. Subject to the determined suitability of the subset of threads, the method determining a thread from the subset of threads to execute the task using content of the cache memory associated with the subset of threads.

Abstract: Disclosed is a method (2500) of determining, for a rendering job (2402) comprising one or more page building jobs, a start time for a print engine (195) to print the rendering job (2402), the method including determining (2502) for the rendering job a current start time for printing based on at least a predicted finishing time of a page building job, determining (2503) a difference between the predicted finishing time and an actual finishing time of the page building job, determining (2504) if, based on the difference, a predetermined condition is satisfied, and if the predetermined criterion is satisfied, determining (2505) an updated start time for printing the rendering job based on information relating to the actual finishing time of the page building job, and starting (2509) the print engine to print the rendering job at the updated start time.

Abstract: The disclosure relates to an image processing system of encoding spectral coefficients of an image. According to the disclosure, the spectral coefficients of the image are received, the spectral coefficients being quantized, and a scaling factor to be applied to the image for rendering a bitmap of the image after decoding is received. The received spectral coefficients are partitioned into a plurality of groupings, wherein a number of coefficients in each of the groupings is determined based on the scaling factor for rendering the bitmap of the image. The spectral coefficients in each of the plurality of groupings are encoded, and the plurality of groupings of encoded spectral coefficients are transmitted to a decoder.

Abstract: A method of determining a thread from a plurality of threads to execute a task in a multi-processor computer system. The plurality of threads is grouped into at least one subset associated with a cache memory of the computer system. The task has a type determined by a set of instructions. The method obtains an execution history of the subset of plurality of threads and determines a weighting for each of the set of instructions and the set of data, the weightings depending on the type of the task. A suitability of the subset of the threads to execute the task based on the execution history and the determined weightings, is then determined. Subject to the determined suitability of the subset of threads, the method determining a thread from the subset of threads to execute the task using content of the cache memory associated with the subset of threads.

Abstract: Disclosed is method of encoding a set of data values (205-245). Each data value corresponds to a pixel position (205,210, 220,225) within an image (100). The method operates on a current (230) said data value at a current pixel position. The method creates (605) a context set (215,225) for the data value (230), the context set including a data value at a pixel position (225) in the set immediately preceding the current pixel position in an encoding order, wherein the immediately preceding pixel position is not adjacent said current pixel position within said image. The method then encodes (500) the data value (230) using the created context set (215,225). A corresponding decoding method is also provided.

Abstract: Disclosed is a method (2500) of determining, for a rendering job (2402) comprising one or more page building jobs, a start time for a print engine (195) to print the rendering job (2402), the method including determining (2502) for the rendering job a current start time for printing based on at least a predicted finishing time of a page building job, determining (2503) a difference between the predicted finishing time and an actual finishing time of the page building job, determining (2504) if, based on the difference, a predetermined condition is satisfied, and if the predetermined criterion is satisfied, determining (2505) an updated start time for printing the rendering job based on information relating to the actual finishing time of the page building job, and starting (2509) the print engine to print the rendering job at the updated start time.

Abstract: A method (700) of storing a bitmap is disclosed. The method (700) examines a transform matrix of a representation of the bitmap to determine a scaling factor required for rendering the bitmap. A range of spectral coefficients is determined based on the scaling factor. Each range of spectral coefficients is entropy encoded into separate bitstreams representing the bitmap. The bitstreams are stored in a computer memory (106).

Abstract: Disclosed is a variable-length image compression arrangement which represents successive distinct image data values (220, 221) of an image using corresponding non-decreasing Palette values (215, 222), and which incorporates (915, 1025) into the encoded data stream information recording the position in the encoded data stream at which each Palette value bit representation length increase occurs.

Abstract: Disclosed is a variable-length image compression arrangement which represents successive distinct image data values (220, 221) of an image using corresponding non-decreasing Palette values (215, 222), and which incorporates (915, 1025) into the encoded data stream information recording the position in the encoded data stream at which each Palette value bit representation length increase occurs.

Abstract: Disclosed is method of encoding a set of data values (205-245). Each data value corresponds to a pixel position (205,210, 220,225) within an image (100). The method operates on a current (230) said data value at a current pixel position. The method creates (605) a context set (215,225) for the data value (230), the context set including a data value at a pixel position (225) in the set immediately preceding the current pixel position in an encoding order, wherein the immediately preceding pixel position is not adjacent said current pixel position within said image. The method then encodes (500) the data value (230) using the created context set (215,225). A corresponding decoding method is also provided.