/usr/share/psychtoolbox-3/PsychDemos/BlurredVideoCaptureDemo.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 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 | function BlurredVideoCaptureDemo(filtertype, kwidth, deviceIndex)
% BlurredVideoCaptureDemo - Show application of image filters to videocaptured images.
%
% This demo shows how to apply 2D convolution kernels to a live video
% stream captured from an attached default camera. Convolution is not
% performed on the cpu by Matlab/Octave, but executed hardware-accelerated
% on the GPU for potentially much higher speed.
%
% Usage:
%
% BlurredVideoCaptureDemo([filtertype=1][, kwidth=11][, deviceIndex=0])
%
% 'filtertype' is optional and can be:
%
% 0 = None.
% 1 = Gaussian blur - This is the default.
% 2 = Prewitt operator.
% 3 = Unsharp operator.
% 4 = Sobel operator.
% 5 = Log operator.
%
% The filters are selected via the fspecial() function, and converted into
% proper convolution kernels. You may need the Matlab image processing
% toolobox or equivalent Octave package installed, for fspecial() to be
% available.
%
% 'kwidth' = Optional convolution kernel width in pixels. Defaults to 11.
%
% 'deviceIndex' = Optional index of the video capture device. Defaults to
% auto-selected default video source.
%
% Press any key to finish the demo.
%
AssertOpenGL;
screen=max(Screen('Screens'));
if nargin < 1 || isempty(filtertype)
filtertype = 1;
end
if nargin < 2 || isempty(kwidth)
kwidth=11;
end
if nargin < 3 || isempty(deviceIndex)
deviceIndex = [];
end
try
InitializeMatlabOpenGL;
win=Screen('OpenWindow', screen, 0);
% Initial flip to a blank screen:
Screen('Flip',win);
% Set text size for info text. 24 pixels is also good for Linux.
Screen('TextSize', win, 24);
% Build a filter kernel:
stddev = kwidth / 3;
switch(filtertype)
case 0
kernel = [];
case 1
kernel = fspecial('gaussian', kwidth, stddev);
case 2
kernel = fspecial('prewitt');
case 3
kernel = fspecial('unsharp');
case 4
kernel = fspecial('sobel');
case 5
kernel = fspecial('log');
end
if filtertype > 0
% Build shader from kernel:
shader = EXPCreateStatic2DConvolutionShader(kernel, 3, 3, 0, 1);
else
% No filtering requested: Select fixed-function pipeline
shader = 0;
end
% Open video capture device:
grabber = Screen('OpenVideoCapture', win, deviceIndex);
% Start video capture:
Screen('StartVideoCapture', grabber);
count = 0;
t=GetSecs;
% Repeat until keypress or timeout of 10 minutes:
while ((GetSecs - t) < 600) && ~KbCheck
% Wait for next video image:
tex = Screen('GetCapturedImage', win, grabber, 1);
% Valid?
if tex > 0
% Draw new video texture from framegrabber.
Screen('DrawTexture', win, tex, [], [], [], [], [], [], shader);
Screen('Close', tex);
% Show it:
Screen('Flip', win);
end
count = count + 1;
end
telapsed = GetSecs - t
% Stop and close video source:
Screen('StopVideoCapture', grabber);
Screen('CloseVideoCapture', grabber);
% Close down everything else:
Screen('CloseAll');
avgfps = count / telapsed
catch
sca;
psychrethrow(psychlasterror);
end
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