Rebol-OpenCV convertTo function

ConvertTo function converts an array to another data type with optional scaling.

For example in a few LOC you can modify the brightness of any image as illustrated below. 

#!/usr/local/bin/r3
Rebol [
]
cv: import opencv
with cv [
alpha: 1.0 ;--scale factor
beta: 64 ;--delta added to the scaled values
filename: %../../image/lena.tiff         ;--file name
img: imread/with filename IMREAD_UNCHANGED ;--load image as is
mat1: convertTo img none CV_8U alpha beta ;--increase the brightness by 64 
mat2: convertTo img none CV_8U alpha negate beta    ;--decrease the brightness by 64 
imshow/name img  "Source" ;--show image 
imshow/name mat1 "High Brightness" ;--show image
imshow/name mat2 "Low Brightness" ;--show image
moveWindow "Source"  260x0 ;--move image
moveWindow "High Brightness" 520x0 ;--move image
moveWindow "Low Brightness" 0x0 ;--move image
waitKey 0 ;--any key to close
]

The result: