"Auto contrast stretch" option in command line

[Paula Sanematsu]

Hello,

I have used the PIVlab_GUI to manually setup each analysis. However, I am getting to a point that I need to automate my analysis. To do so, I am planning to use PIVlab_commandline.m file. As a test, I am trying to use the PIVlab_commandline.m to reproduce a session that I did using the PIVlab_GUI

I currently have the "Auto contrast stretch" enabled in the GUI, but I fail to see that in both PIVlab_commandline.m and PIVlab_preproc.m files. How do enable "Auto contrast stretch" while using the PIVlab_commandline.m file?

Thank you,
Paula

[Benja Perez]

Hello,

I probably arrived late but it may be useful to someone. You can apply the function strechlim to any frame and then load that to the intensity values in the preprocessing settings. I attach an example.

% Calculation of the limits based on the initial frame (not exactly what is done when using the Pivlab GUI, but works unless you have considerable intensity differences between frames)

initial_frame = imread(fullfile(directory, '0001.tif'));  % Load a frame before settings

stretcher = stretchlim(initial_frame); % Calculation of the limits

minintens = stretcher(1);

maxintens = stretcher(2);

% Setting of the constrast strech in the commandline (in the section of preprocessing settings)

p{9,1}= 'Minimum intensity'; p{9,2}=minintens; % Minimum intensity of input image (0 = no change)

p{10,1}='Maximum intensity'; p{10,2}=maxintens; % Maximum intensity on input image (1 = no change)

I hope this can help ;)

Benjamin