Sixel: Difference between revisions
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Bands are separated by hyphens ('-'). Return to the start of a band without moving to the next one (i.e. to draw another color) with '$'. The same number of sixels ought be provided for each color used in a band (but they may of course be the empty sixel). For each sixel, determine which of the six pixels 0..5 (0 on the top, 5 on the bottom) match the color, and and for each pixel N, add 2ⁿ. The result will be between 0 and 63, inclusive. Add 63 to this total; the sixel is the corresponding ASCII character (between 63 and 126, inclusive). When a sixel is repeated four or more times in a row, use "!n" to runlength encode the series. | Bands are separated by hyphens ('-'). Return to the start of a band without moving to the next one (i.e. to draw another color) with '$'. The same number of sixels ought be provided for each color used in a band (but they may of course be the empty sixel). For each sixel, determine which of the six pixels 0..5 (0 on the top, 5 on the bottom) match the color, and and for each pixel N, add 2ⁿ. The result will be between 0 and 63, inclusive. Add 63 to this total; the sixel is the corresponding ASCII character (between 63 and 126, inclusive). When a sixel is repeated four or more times in a row, use "!n" to runlength encode the series. | ||
If a given pixel is unspecified (i.e. no band includes the pixel), the behavior is dependent on whether the Set Raster Attributes control sequence has been emitted. If it has, unspecified pixels are drawn with Color Register 0. If it has not, they are not touched. For transparency with regards to existing material, then, Set Raster Attributes must not be used. | |||
===Color registers=== | ===Color registers=== | ||