Abstract: A method and compression unit for compressing a block of image data to satisfy a target level of compression, wherein the block of image data comprises a plurality of image element values, each image element value comprising one or more data values relating to a respective channel. For each of the channels: (i) an origin value for the channel for the block is determined, (ii) difference values are determined representing differences between the data values and the determined origin value for the channel for the block, and (iii) a first number of bits for losslessly representing a maximum difference value of the difference values for the channel for the block is determined.

Abstract: A decompression method determines image element values from compressed data representing a block of image element values relating to a respective one or more channels. For each of the channels, an indication of a first number of bits representing difference values between the data values and an origin value for the channel is read from the compressed data. For each of the channels, a second number of bits is obtained, wherein representations of the difference values for each of the channels are included in the compressed data using the second number of bits for that channel. The obtained second numbers of bits for the respective channels are used to read the representations of the difference values for the image element values being decompressed. Based on the representations of the difference values, a difference value is determined in accordance with the first number of bits for the channel.

Abstract: A method and compression unit for compressing a block of image data to satisfy a target level of compression, wherein the block of image data comprises a plurality of image element values, each image element value comprising one or more data values relating to a respective channel. For each of the channels: (i) an origin value for the channel for the block is determined, (ii) difference values are determined representing differences between the data values and the determined origin value for the channel for the block, and (iii) a first number of bits for losslessly representing a maximum difference value of the difference values for the channel for the block is determined.

Abstract: A decompression method determines image element values from compressed data representing a block of image element values relating to a respective one or more channels. For each of the channels, an indication of a first number of bits representing difference values between the data values and an origin value for the channel is read from the compressed data. For each of the channels, a second number of bits is obtained, wherein representations of the difference values for each of the channels are included in the compressed data using the second number of bits for that channel. The obtained second numbers of bits for the respective channels are used to read the representations of the difference values for the image element values being decompressed. Based on the representations of the difference values, a difference value is determined in accordance with the first number of bits for the channel.

Abstract: A method and compression unit for compressing a block of image data to satisfy a target level of compression, wherein the block of image data comprises a plurality of image element values, each image element value comprising one or more data values relating to a respective channel. For each of the channels: (i) an origin value for the channel for the block is determined, (ii) difference values are determined representing differences between the data values and the determined origin value for the channel for the block, and (iii) a first number of bits for losslessly representing a maximum difference value of the difference values for the channel for the block is determined.

Abstract: A method and compression unit for compressing a block of image data to satisfy a target level of compression, wherein the block of image data comprises a plurality of image element values, each image element value comprising one or more data values relating to a respective channel. For each of the channels: (i) an origin value for the channel for the block is determined, (ii) difference values are determined representing differences between the data values and the determined origin value for the channel for the block, and (iii) a first number of bits for losslessly representing a maximum difference value of the difference values for the channel for the block is determined.

Abstract: A decompression method determines image element values from compressed data representing a block of image element values relating to a respective one or more channels. For each of the channels, an indication of a first number of bits representing difference values between the data values and an origin value for the channel is read from the compressed data. For each of the channels, a second number of bits is obtained, wherein representations of the difference values for each of the channels are included in the compressed data using the second number of bits for that channel. The obtained second numbers of bits for the respective channels are used to read the representations of the difference values for the image element values being decompressed. Based on the representations of the difference values, a difference value is determined in accordance with the first number of bits for the channel.

Abstract: A method and decompression unit for performing decompression to determine image element values from compressed data representing a block of image element values each comprising one or more data values relating to a respective one or more channels. An indication of an origin value for each of the channels is read from the compressed data. For each of the channels, an indication of a first number of bits for representing difference values between the data values and the origin value for the channel is read from the compressed data. For each of the one or more channels, a second number of bits is obtained, wherein representations of the difference values for each of the channels are included in the compressed data using the second number of bits for that channel. The obtained second numbers of bits for the respective channels are used to read the representations of the difference values for the image element values being decompressed from the compressed data.

Abstract: A method and compression unit for compressing a block of image data to satisfy a target level of compression, wherein the block of image data comprises a plurality of image element values, each image element value comprising one or more data values relating to a respective channel. For each of the channels: (i) an origin value for the channel for the block is determined, (ii) difference values are determined representing differences between the data values and the determined origin value for the channel for the block, and (iii) a first number of bits for losslessly representing a maximum difference value of the difference values for the channel for the block is determined.

Abstract: A method and decompression unit for performing decompression to determine image element values from compressed data representing a block of image element values each comprising one or more data values relating to a respective one or more channels. An indication of an origin value for each of the channels is read from the compressed data. For each of the channels, an indication of a first number of bits for representing difference values between the data values and the origin value for the channel is read from the compressed data. For each of the one or more channels, a second number of bits is obtained, wherein representations of the difference values for each of the channels are included in the compressed data using the second number of bits for that channel. The obtained second numbers of bits for the respective channels are used to read the representations of the difference values for the image element values being decompressed from the compressed data.

Abstract: An apparatus for providing a number of ports with burst access to a DRAM array includes a memory array, a controller for controlling the memory array, a write device for writing to the memory array, a read device for reading from the memory array, a FIFO output buffer for temporarily storing data read from the memory array and/or a FIFO input buffer for temporarily storing data prior to writing to the memory array.