ISO/EC CD15444-1: 1999(V1.0,9 December 1999) code-block scan: The order in which the coefficients within a code-block are visited during a coding pass. The code-block is processed in stripes, each consisting of four rows and spanning the width of the code-block. Each stripe is processed column by column from left to right and from top to bottom coder: An embodiment of either an encoding or decoding process coding pass: A complete pass through a code-block where the appropriate coefficient values and context are applied. There are three types of coding passes: significance propagation pass, magnitude refinement pass and cleanup pass colour image: An image that has more than one component component: An image consists of one or more components. Each component is a two-dimensional array of samples. A colour image typically consists of several components such as RGB compressed data: Portion of the codestream, tile, or packet that contains the bit stream description. conforming reader: An application that reads and interprets a JP2 file correctly as defined by this context: Function of samples previously decoded used to condition the coding of the present sample. context label: The arbitrary index used to distinguish different context values. The labels are used as a convenience of notation rather than being normative context modelling: Procedure determining the probability distribution of difference with predicted bit from context vector: The binary vector consisting of the significance states of its context neighbor coefficients decoder: An embodiment of a decoding process, and optionally a colour transformation process. decoding process: A process which takes as its input compressed data and outputs a reconstructed image data. decomposition level: A collection of wavelet sub-bands where each coefficient has the same span with respect to the original samples. These include HL, LH, HH and, for the highest decomposition level, LL sub-bands. In this specification, only the ll sub-band can be further decomposed. discrete wavelet transform: DWT. a wavelet transformation performed on, and resulting in, spatiall encoder: An embodiment of an encoding process encoding process: A process, which takes as its input a source image and outputs compressed image data file format: This consists of a codestream and additional support data and information not explicitly required for the decoding of image data. Examples of such support data are text fields providing titling, security and historical information, markers to support placement of multiple codestreams within a given data file, and markers to support exchange between platforms or conversion to other file formats HH sub-band: The sub-band obtained by forward horizontal high-pass analysis filtering and vertical high pass analysis filtering. This sub-band contributes to reconstruction with inverse horizontal low-pass synthesis ltering and vertical low-pass synthesis filtering HL sub-band: The sub-band obtained by forward horizontal high-pass analysis filtering and vertical low-pass nalysis filtering. This sub-band contributes to reconstruction with inverse horizontal low-pass synthesis filtering and vertical high-pass synthesis filtering image: A set of two-dimensional arrays(components)of data image area: A rectangular part of the reference grid, registered by offsets from the origin and having the size of the image. The components are contained within this area and are related to the reference grid with respect image area offset: The width and height down and to the right of the reference origin where the origin of the mage area can be found ITU-T Rec T 800(1999 CDV10) 3ISO/IEC CD15444-1 : 1999 (V1.0, 9 December 1999) ITU-T Rec. T.800 (1999 CDV1.0) 3 code-block scan: The order in which the coefficients within a code-block are visited during a coding pass. The code-block is processed in stripes, each consisting of four rows and spanning the width of the code-block. Each stripe is processed column by column from left to right and from top to bottom. coder: An embodiment of either an encoding or decoding process. coding pass: A complete pass through a code-block where the appropriate coefficient values and context are applied. There are three types of coding passes: significance propagation pass, magnitude refinement pass and cleanup pass. colour image: An image that has more than one component. component: An image consists of one or more components. Each component is a two-dimensional array of samples. A colour image typically consists of several components such as RGB. compressed data: Portion of the codestream, tile, or packet that contains the bit stream description. conforming reader: An application that reads and interprets a JP2 file correctly as defined by this Recommendation | International Standard. context: Function of samples previously decoded used to condition the coding of the present sample. context label: The arbitrary index used to distinguish different context values. The labels are used as a convenience of notation rather than being normative. context modelling: Procedure determining the probability distribution of difference with predicted bit from the context. context vector: The binary vector consisting of the significance states of its context neighbor coefficients decoder: An embodiment of a decoding process, and optionally a colour transformation process. decoding process: A process which takes as its input compressed data and outputs a reconstructed image data. decomposition level: A collection of wavelet sub-bands where each coefficient has the same span with respect to the original samples. These include HL, LH, HH and, for the highest decomposition level, LL sub-bands. In this specification, only the LL sub-band can be further decomposed. discrete wavelet transform: DWT. A wavelet transformation performed on, and resulting in, spatially discrete coefficients. encoder: An embodiment of an encoding process. encoding process: A process, which takes as its input a source image and outputs compressed image data. file format: This consists of a codestream and additional support data and information not explicitly required for the decoding of image data. Examples of such support data are text fields providing titling, security and historical information, markers to support placement of multiple codestreams within a given data file, and markers to support exchange between platforms or conversion to other file formats HH sub-band: The sub-band obtained by forward horizontal high-pass analysis filtering and vertical high￾pass analysis filtering. This sub-band contributes to reconstruction with inverse horizontal low-pass synthesis filtering and vertical low-pass synthesis filtering. HL sub-band: The sub-band obtained by forward horizontal high-pass analysis filtering and vertical low-pass analysis filtering. This sub-band contributes to reconstruction with inverse horizontal low-pass synthesis filtering and vertical high-pass synthesis filtering. image: A set of two-dimensional arrays (components) of data. image area: A rectangular part of the reference grid, registered by offsets from the origin and having the size of the image. The components are contained within this area and are related to the reference grid with respect to this area. image area offset: The width and height down and to the right of the reference origin where the origin of the image area can be found