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Diffstat (limited to 'man/man7/image.7')
| -rw-r--r-- | man/man7/image.7 | 46 |
1 files changed, 23 insertions, 23 deletions
diff --git a/man/man7/image.7 b/man/man7/image.7 index 6e613f9c..bfb299bd 100644 --- a/man/man7/image.7 +++ b/man/man7/image.7 @@ -5,9 +5,9 @@ image \- external format for images .B #include <draw.h> .SH DESCRIPTION Images are described in -.IR graphics (3), +.MR graphics (3) , and the definition of pixel values is in -.IR color (7). +.MR color (7) . Fonts and images are stored in external files in machine-independent formats. .PP @@ -21,7 +21,7 @@ and and .B writememimage (see -.IR memdraw (3)). +.MR memdraw (3) ). An uncompressed image file starts with 5 strings: .BR chan , @@ -34,10 +34,10 @@ Each is right-justified and blank padded in 11 characters, followed by a blank. The .B chan value is a textual string describing the pixel format -(see +(see .B strtochan in -.IR graphics (3) +.MR graphics (3) and the discussion of channel descriptors below), and the rectangle coordinates are decimal strings. The rest of the file contains the @@ -49,7 +49,7 @@ consists of the byte containing pixel .B r.min.x and all the bytes up to and including the byte containing pixel .BR r.max.x -1. -For images with depth +For images with depth .I d less than eight, a pixel with x-coordinate = .I x @@ -73,11 +73,11 @@ The and .B unloadimage functions described in -.IR allocimage (3) +.MR allocimage (3) also deal with rows in this format, stored in user memory. .PP The channel format string is a sequence of two-character channel descriptions, -each comprising a letter +each comprising a letter .RB ( r for red, .B g @@ -95,10 +95,10 @@ and for ``don't care'') followed by a number of bits per pixel. The sum of the channel bits per pixel is the -depth of the image, which must be either +depth of the image, which must be either a divisor or a multiple of eight. It is an error to have more than -one of any channel but +one of any channel but .BR x . An image must have either a greyscale channel; a color mapped channel; or red, green, and blue channels. @@ -110,13 +110,13 @@ In particular .B 'r8g8b8' pixels have byte ordering blue, green, and red within the file. See -.IR color (7) +.MR color (7) for more details of the pixel format. .PP A venerable yet deprecated format replaces the channel string with a decimal .IR ldepth , -which is the base two logarithm of the number +which is the base two logarithm of the number of bits per pixel in the image. In this case, .IR ldepth s @@ -177,9 +177,9 @@ Some small images, in particular 48\(mu48 face files as used by .I seemail (see Plan 9's -\fIfaces\fR(1) +.IR faces (1) and -.IR face (7)) +.MR face (7) ) and 16\(mu16 cursors, can be stored textually, suitable for inclusion in C source. Each line of text represents one scan line as a @@ -188,18 +188,18 @@ bytes, shorts, or words in C format. For cursors, each line defines a pair of bytes. (It takes two images to define a cursor; each must be stored separately to be processed by programs such as -.IR tweak (1).) +.MR tweak (1) .) Face files of one bit per pixel are stored as a sequence of shorts, those of larger pixel sizes as a sequence of longs. Software that reads these files must deduce the image size from the input; there is no header. These formats reflect history rather than design. .SH "SEE ALSO" -.IR jpg (1), -.IR tweak (1), -.IR graphics (3), -.IR draw (3), -.IR allocimage (3), -.IR color (7), -.IR face (7), -.IR font (7) +.MR jpg (1) , +.MR tweak (1) , +.MR graphics (3) , +.MR draw (3) , +.MR allocimage (3) , +.MR color (7) , +.MR face (7) , +.MR font (7) |