histog(3G)

NAME
     hstgrm -  modifies pixel transfers to compute a histogram

FORTRAN SPECIFICATION
     subroutine hstgrm(op, value)
     integer*4 op
     integer*4 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.