hgram(3G) hgram(3G)
NAME
hgram - modifies pixel transfers to compute a histogram
C SPECIFICATION
void hgram(unsigned long op, unsigned long value)
PARAMETERS
op one of the symbolic constants:
(parameters that affect lrectread, lrectwrite, rectcopy pixel
transfers)
HIST_ENABLE, default value:0. Enable hgram in lrectread, lrectwrite
and rectcopy pixel transfers. Value specifies the number of equally
spaced bins in the histogram. Valid values: 1 to 4096.
HIST_DISABLE, disable hgram.
HIST_CLEAR, clear every histogram bin to value
value
specifies the number of equally spaced bins in histogram if op is
HIST_ENABLE. Valid values: 1 to 4096. specifies the value to clear
the histogram to if op is HIST_CLEAR.
DESCRIPTION
hgram allows enabling and disabling of the collection of histogram data
during pixel transfer operations (e.g., rectcopy, lrectread, and
lrectwrite). When hgram is enabled, the destination of the pixel transfer
operation is unaffected by the pixel transfer operation. The histogram
bins can be initialized by HIST_CLEAR. Enabling and disabling of hgram
do not initialize the histogram, the initialization is done through
HIST_CLEAR.
SEE ALSO
gethgram minmax getminmax pixeltransfer pixelmap pixmode
NOTES
hgram only works on RealityEngine systems running 5.0.1 or greater.
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