Returns thecontents of the specified rectangular portion of a displayed image.
The starting column of data to read.y0
The starting row of data to read.nx
The number of columns to read.ny
The number of rows to read.channel
(optional) The memory channel to be read. If not specified, it is assumed to be zero. This parameter is ignored on display systems that only have one memory channel.
Byte array of dimensions nx-by-ny.
UNIX and OpenVMS Users: If the display is a 24-bit display, and both the channel parameter and True keyword are absent, the maximum RGB value in each pixel is returned.
The memory channel to be read. This keyword is identical to the channel input parameter; only one needs to be specified.Order
If specified, overrides the current setting of the !Order system variable for the current image only. If nonzero, Order causes the image to be drawn from the top-down, instead of from the bottom-up (the default).True
(UNIX/OpenVMS Only) If present and nonzero, indicates that a true-color (24-bit) image is to be read and specifies the index of the dimension over which color is interleaved:
For more information, see Image Display Routines: TV and TVSCL in Chapter 6 of the PV-WAVE User's Guide.
