# Img Manual

Introduction | Installation | Format handlers | External libraries

### Format handlers

The pixmap image type can be used as follows:
  image create pixmap -file
or
  image create pixmap -data ;#(in XPM format)

The photo image type works the same:
  image create photo -file
or
  image create photo -data ;#(in any of the supported formats, base-64 encoded)

Valid format specifiers for reading photo's:

| "bmp"
| "gif -index <n>"
| "jpeg -fast -grayscale"
| "png"
| "tiff"
| "xbm"
| "xpm"
| "postscript -index <n> -zoom <x> <y>" | (-index not yet implemented)
| "window" | (works only with "-data", not "-file")

Valid format specifiers for writing photo's:

| "bmp"
| "gif -interlaced <bool>"
| "jpeg -quality <n> -smooth <n> -grayscale -optimize -progressive"
| "png Author <name> Title <title> Description ....." Each pair of arguments will add a named text chunk to the file.
| "tiff -compression -byteorder "
| "xbm"
| "xpm"

If wish is patched, "imageName write" has the additional options "-background" and "-grayscale". "imageName put" has the additional option "-format". In addition there is a new command "imageName data", which allows the options "-background", "-format", "-from" and "-grayscale".

The format options have the following meaning:

| -background C: | use color C as background color for transparent parts of the image.
| -byteorder: | Byteorder for TIFF file. Should be one of bigendian, littleendian, network, smallendian or {}. Default: {}
| -compression: | Compression for TIFF file. Should be one of none, lzw, jpeg, packbits or deflate. Default: none.
| -fast: | Fast, low-quality processing.
| -grayscale: | Force incoming image to grayscale/ Create monochrome file.
| -index N: | Select one of the sub-images (GIF and postscript only, not yet implemented for postscript). Default value: 0
| -interlaced N: | N=1: interlaced. N=0: non-interlaced.
| -optimize: | Optimize Huffman table.
| -progressive: | Create progressive file (JPEG only).
| -quality N: | Compression quality (0..100; 5-95 is useful range). Default value: 75
| -smooth N: | Perform smoothing (10-30 is enough for most GIF's). Default value: 0
| -zoom X Y: | Multiply image size by given scale factors. If Y is missing, the default is the same as X. X and Y are allowed to be in floating point format, but they are rounded to the nearest practically possible value. For postscript this means the zoom factors should be multiples of 1/72.