DC_WRITE_DIB Function (Windows)

Writes image data from a variable to a Device Independent Bitmap (DIB) format file.

status = DC_WRITE_DIB(filename, imgarr)

filename A string containing the pathname and filename of the DIB file.

imgarr The variable containing the image data to be saved as a DIB file.

status Value returned by DC_WRITE_DIB; expected values are:

Keywords

ColorClass An integer specifying the DIB color class level. If not provided, ColorClass=2 is assumed. Valid values are 2, 16, and 256.

ColorsUsed The number of colors that the bitmap image uses. If this keyword is not provided, it is set to the number of elements in SystemPalette or Palette if one of them is provided; otherwise, ColorsUsed defaults to 2.

Compression A string that specifies the kind of image data compression to use as the data is written to the file. This keyword is valid only if ColorClass is specified as 16 or 256. If this keyword is not provided, no compression is performed. Valid values are:

'None' None (no compression)

'RLE4' Run-length encoded format for bitmaps with 4 bits per pixel

'RLE8' Run-length encoded format for bitmaps with 8 bits per pixel

ImportantColors The number of important colors that the bitmap image needs to display. If not provided, ImportantColors defaults to 0.

Palette Specifies a color table to be saved with the DIB file. Palette must be a 3-by-n array of integers, where n is either 1, 16, or 256. n specifies the number of colors associated with the bitmap. If the ColorClass keyword is set to 2, then the Palette keyword is ignored and a monochrome color table is saved.

SystemPalette If set to a nonzero value, this keyword causes the system color table to be saved with the DIB file. SystemPalette always takes precedence over the Palette keyword.

Device Independent Bitmap (DIB) is a bitmap format that is useful for transporting graphics and color table information between different devices and applications in the Windows environment. DIB files can be produced by graphics applications such as Microsoft Image Editor, Microsoft Paintbrush, and PV-WAVE.

You must specify a color table to be saved with the DIB file, or an error is returned. The Palette and SystemPalette keywords let you specify a color table.

DC_WRITE_DIB exports DIB images from PV-WAVE. It handles: 1) opening the file, 2) assigning it a logical unit number (LUN), and 3) closing the file when you are done writing the data.

If imgarr is not a 2- or 3-dimensional byte array, the function DC_WRITE_DIB returns an error status and no data is written to the output file.

If the variable maverick is a 512-by-512 byte array, the function call:

status = DC_WRITE_DIB('mav.gif', maverick,  $
    ColorClass = 256, Compression = None',  $
    /SystemPalette)

creates the file mav.gif and uses it to store the system color table and the image data contained in the variable maverick. The created DIB file is not compressed and has a color class of 256.

DC_READ_DIB, WREAD_DIB, WWRITE_DIB

For more information, see the PV-WAVE Programmer's Guide.