VISHIST (Statement)


Obtain the histogram (brightness distribution) of the screen.


VISHIST <window number>, <coordinate X>, <coordinate Y>


<window number>
Specifies the window number (0 to 511).
<coordinate X>
Specifies the X coordinate (0 to 511).
<coordinate Y>
Specifies the Y coordinate (0 to 479).
  • Specifies the process area with a window.
  • If the designated window position is out of screen, the execution will result in an error.
  • The only possible window shape that you may designate is a rectangle with 0 degrees. If another window shape is designated, an error will result.
  • The processing object is the screen designated with VISWORKPLN.
  • It is possible to read the processing result with the VISREFHIST instruction.
  • The memory stores the processing result. It will be kept until this instruction is executed again.
  • For this instruction, a µVision board (option) is required.



WINDMAKE R,1,100,100,0,2
'Set window 1 to rectangle
CAMIN 1
'Obtain a camera image from the storage memory
VISWORKPLN 0
'Set the processing object screen for storage memory 0
VISHIST 1,100,100
'Execute the histogram for window 1 with the coordinates
'(100, 100) as the home position
FOR I1 = 0 TO 255
I2 = VISREFHIST(I1)
'Assign the distribution data of
'the brightness value I1 to I2
VISLOC 10, 10
'Set the display position
VISDEFCHAR 1,1,3
'Designate the display character size
'and the display mode
VISPRINT "Distribution data=";I2
NEXT I1


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