/usr/share/psychtoolbox-3/PsychAlphaBlending/AlphaSum.m is in psychtoolbox-3-common 3.0.11.20140816.dfsg1-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 | function sumImage=AlphaSum(imageSource, imageDestination)
% sumImage=AlphaSum(image1, image2)
%
% Return the sum of two images combined with alpha blending as would
% Screen.
%
% see also: AlphaSourceProduct, AlphaDestinationProduct, PsychAlphaBlending
% HISTORY
%
% mm/dd/yy
%
% 2/11/05 awi wrote it.
sumImage=imageSource + imageDestination;
sumImageOver=sumImage > 255;
sumImage(sumImageOver)=255;
%sumImage=round(sumImage);
|