/usr/share/psychtoolbox-3/PsychAlpha/ImageUndistortionDemo.m is in psychtoolbox-3-common 3.0.12.20160126.dfsg1-1ubuntu1.
This file is owned by root:root, with mode 0o644.
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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 | function ImageUndistortionDemo(calibfilename, imagefilename)
% ImageUndistortionDemo(calibfilename [, imagefilename])
%
% A very sketchy demo on how to do gpu accelerated geometric
% undistortion of images.
%
% 'calibfilename' Name of a calibration file, as also used by
% PsychImaging's 'GeometryCorrection' tasks, and generated by one
% of the available calibration procedures, e.g., DisplayUndistortionBVL,
% DisplayUndistortionCSV, DisplayUndistortionBezier, ...
%
% 'imagefilename' Optional name of image file to process. If left out,
% our standardy bunny image will be used. If set to 'checkerboard', a
% checkerboard pattern will be used.
%
% Press any key to exit the demo after the undistorted image was
% displayed.
%
% This demo is more a template for you to get started writing suitable
% code for your purpose than a ready made plug & play solution.
%
% History:
% 7/27/2008 mk Written.
% 7/25/2015 mk Updated.
% Basic check if runnning on PTB-3:
AssertOpenGL;
if nargin < 1 || isempty(calibfilename)
error('Required calibfilename missing.');
end
if nargin < 2
imagefilename = [];
end
if isempty(imagefilename)
imagefilename = [PsychtoolboxRoot 'PsychDemos/konijntjes1024x768.jpg'];
end
% Choose output screen as usual:
screenid=max(Screen('Screens'));
% Only enable support for fast offscreen windows, don't need full blown pipeline here:
PsychImaging('PrepareConfiguration');
PsychImaging('AddTask', 'General', 'UseFastOffscreenWindows');
w=PsychImaging('OpenWindow', screenid, 0);
if ~strcmpi(imagefilename, 'checkerboard')
% Use our standard bunny picture as some test case:
img = imread(imagefilename);
else
% Use a checkerboard pattern:
[ww, wh] = Screen('WindowSize', w);
checkSize = 105;
img = 255 * double(checkerboard(checkSize,round(wh/checkSize/2),round(ww/checkSize/2)) > 0.5);
end
mytex=Screen('MakeTexture', w, img);
% Size of input image to apply correction to -- The size of the offscreen window:
srcSize = Screen('Rect', mytex);
% Setup oversized offscreen window: This as an example of an oversized
% input image buffer. Could also use a normal texture from
% Screen('MakeTexture') or any other function that returns texture handles:
[exampleImage, woffrect] = Screen('OpenOffscreenWindow', w, 0, srcSize);
% Create an offscreen window of the size of the wanted undistorted and
% scaled down image, as a target buffer:
undistortedImage = Screen('OpenOffscreenWindow', w, 128, srcSize);
% Create an empty image processing operator for onscreen window 'w':
gloperator = CreateGLOperator(w);
% Create and add image undistortion operation to gloperator:
% Setup calibration: 'calibfilename' is the path to the calibration file
% that defines undistortion and scaling: 73, 73 is resolution of warp-mesh,
% if the used calibration method is DisplayUndistortionBVL, otherwise the
% resolution parameters are ignored by the other calibration methods.
%
% Higher numbers for mesh resolution == finer undistortion but longer draw
% time. 'exampleImage' must be the handle to a texture or offscreen window
% that has the same size, color depth and format as the input images you're
% gonna use later on, otherwise weird things will happen.
AddImageUndistortionToGLOperator(gloperator, exampleImage, calibfilename, 0, 73, 73);
% Draw original image into exampleImage, scale it up to offscreen window size:
Screen('DrawTexture', exampleImage, mytex, [], woffrect);
% Draw some centered text for illustration...
Screen('TextSize', exampleImage, 64);
DrawFormattedText(exampleImage, 'Hello World', 'center', 'center', [0 255 0]);
% Ok, exampleImage contains the "distorted" oversized image we want to
% undistort and scale by application of our gloperator. Apply it,
% undistortedImage will contain the new undistorted image:
undistortedImage = Screen('TransformTexture', exampleImage, gloperator, [], undistortedImage);
% Draw undistorted image to onscreen window:
Screen('DrawTexture', w, undistortedImage);
% Show it:
Screen('Flip', w);
% Wait for keypress:
KbStrokeWait;
% Close all windows and ressources:
Screen('CloseAll');
return;
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