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Package pnm (in pnm.i) -
Index of documented functions or symbols:
DOCUMENT color_image= pnm_colorize(image) colorize the width-by-height array IMAGE, returning a 3-by- width-by-height array, suitable for use with pnm_write. The current graphics palette is used to perform the colorization. The keywords cmin=, cmax=, and top= are recognized and have the same meaning as for the plf, pli, and bytscl functions.
DOCUMENT pnm_display, image
Attempt to display the IMAGE with the pli command and a pseudo-color
palette. The IMAGE must be a 3-by-width-by-height array of RGB
pixel values. If called as a function, the return value is the
width-by-height array of pixels which index into the new palette.
The palette is returned as the external variables red, green, and
blue. The new palette is both coarse and slow to compute.
The size= keyword can be used to set the palette size. The default
is 200 colors, the size of all the distribution palettes.
The flip=1 keyword can be used to flip the image bottom for top.
The square=1 limits flag is set; use
limits,square=0
to return to the default non-square plot limits.
SEE ALSO: pnm_read
DOCUMENT image= pnm_read(filename)
or image= pnm_read(filename, noflip)
read a PBM, PGM, or PPM image from FILENAME. PBM and PGM files
result in width-by-height arrays; PPM files result in 3-by-width-
by-height arrays. If NOFLIP is present and non-zero, the returned
image is in exactly the order stored in FILENAME. Otherwise, the
height dimension is reversed, since images in the files read top
to bottom, while the Yorick image plotting commands go bottom to
top.
SEE ALSO: pnm_display, pnm_write
DOCUMENT pnm_write, image, filename)
or pnm_write, image, filename, noflip)
write IMAGE to a PBM, PGM, or PPM file called FILENAME. If
NOFLIP is present and non-zero, the image in FILENAME is stored
in exactly the order of IMAGE in memory. Otherwise, the height
dimension is reversed, since images in the files read top to
bottom, while the Yorick image plotting commands go bottom to
top.
If IMAGE is a 3-by-width-by-height array, a PPM will be written.
Otherwise, IMAGE must be a width-by-height array. If IMAGE
contains at most two distinct values, a PBM will be written,
otherwise a PGM. You can force a PGM using the bits=8 keyword.
If IMAGE is of type char, it will be used as is, otherwise it
will be scaled to the range 0 to 255. (Note that for a PPM, this
means the largest single rgb component value sets the scale.)
If the text= keyword is present and non-zero, a text PNM file
will be written; the default is to write a binary or raw PNM.
If the noscale=1 keyword is supplied, the IMAGE will not be
scaled to the range 0 to 255. In this case, the IMAGE must
have an integer data type with minimum value >=0. Note that
if max(image)>255, a text PGM or PPM file will be written
(overriding the text= keyword). Raw PNM is char-only.
If bits= is not specified, then noscale=1 forces pnm_write to
guess the value you intended the brightest component value.
If IMAGE is not color, the guess is bits=1 if there are only
1 or 2 values, bits=8 if max(IMAGE)<256, and bits=16 otherwise.
For color IMAGE, the guess is either bits=8 or bits=16.
Normally, PGM and PPM files have a pixel or color component
size of 8 bits, so they run from 0 (darkest) to 255 (brightest).
With bits= you can force a different maximum value. Use bits=8
to force a binary IMAGE to be written as a PGM. The largest
legal value of bits is 16, the smallest is 1.
SEE ALSO: pnm_colorize, pnm_read