RETRO (vipl) functions
LIBRARY ROUTINE
lvtilt - Adds a specified plane to the input image to correct for a tilt in the image luminance.
LIBRARY CALL
int lvtilt(
xvimage *img1,
xvimage *img2,
int mflg,
float xslope,
float yslope)
INPUT
- img1 - input/output image xvimage structure
- img2 - input mask image
- mflg - set to one if img2 to is to be used as a mask image
xslope &
- yslope - specify the characteristics of the plane
and must be given in units per pixel.
OUTPUT
- img1 - input/output image xvimage structure
RETURN VALUE
TRUE (1) on success, FALSE (0) on failure
DESCRIPTION
lvtilt adds a specified plane to the input image
to correct for a tilt in the image luminance.
Often an image will have a skew in the grey level
values that represents a plane with a certain
slope. The tilt takes the form of a plane which
has a X and Y zero crossing at the center of the
input image with xslope and yslope as specified
in the argument line.
img1 is the input and output xvimage structure.
This is done to save space, but you must be
careful not to overwrite important data. img2
is the mask image, if mflg is set then the mask
image is used to gate the operation. A non-zero
mask pixel enables the ouput pixel to contain
adjusted values. A zero mask pixel just transfers
the value of the corresponding pixel in the input
image to the output image. The input images must
be of the same data type and size.
xslope and yslope specify the characteristics of
the plane and must be given in units per pixel.
The output image data type is the same as the
input data type.
ADDITIONAL INFORMATION
none
EXAMPLES
none
SIDE EFFECTS
none
RESTRICTIONS
lvtilt will not operate on COMPLEX or BIT data
storage type images.
MODIFICATION
John Rasure, Marcelo Teran, Donna Koechner
Mon Jun 11 16:53:44 MDT 1990 Donna Koechner - updated to
ghostwriter
Fri Jun 28 16:43:19 MDT 1991 Scott Wilson - Fixed bogous
pointer increment
in float loop with
mask
FILES
$RETRO/objects/library/vipl/src/lvtilt.c
SEE ALSO
vipl(3)
COPYRIGHT
Copyright (C) 1993 - 1997, Khoral Research, Inc. ("KRI") All rights reserved.