RETRO (vipl) functions
LIBRARY ROUTINE
lvhxray - Enhance images using histogram stretch or equalization with overlapping windows.
LIBRARY CALL
int lvhxray(
xvimage *image,
int type,
int xsize,
int ysize)
INPUT
- image - the input image
- type - 1 = do histogram equalization.
2 = do histogram stretch.
- xsize - window width size
- ysize - window heigth size
OUTPUT
- image - after the enhancement
RETURN VALUE
TRUE (1) on success, FALSE (0) on failure *
DESCRIPTION
This module will enhance an image by using a histogram
stretch or histogram equalization method. Vhxray will use
overlapping windows over the entire image, and for each
window compute the histogram and perform a stretch or
equalization. The middle pixel of the window is updated
according to the new histogram value.
The window size must be odd (3x3, 5x5, 15x15, etc), since
we must have a center pixel to update for each window.
The default window size is 5x5.
Since windows are being used, the border pixels will not be
updated. the border pixels will be set to zero, black. The
border size can be calculated as follows:
window width / 2 = side border,
window heigth / 2 = top & bottom border.
The histogram stretch algorithm will stretch the histogram
out as must as possible. The equalization algorithm is
standard.
ADDITIONAL INFORMATION
none
EXAMPLES
none
SIDE EFFECTS
none
RESTRICTIONS
lvhxray will only work on BYTE images.
MODIFICATION
none
FILES
$RETRO/objects/library/vipl/src/lvhxray.c
SEE ALSO
vipl(3)
COPYRIGHT
Copyright (C) 1993 - 1997, Khoral Research, Inc. ("KRI") All rights reserved.