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Unformatted text preview: To display image: 1. For color image, use [img,map]=imread(‘bla.jpg’); %read in the image to matrix img and the colormap into map figure, image(img), axis equal, colormap(map) %This will display the color image 2. For gray image, use img=imread(‘bla.jpg’); %read in the image to matrix img figure, imagesc(img), axis equal, colormap(gray) % intensity will be scaled (while image() won’t) The Image Processing Toolbox comes with imshow() that takes care of color and gray automatically. To convert from rgb to gray: Suppose you have a RGB image (of double class), use the standard NTSC conversion formula intensity = 0.2989*red + 0.5870*green + 0.1140*blue The following code show this: % Assume you have an RGB image of class double, or create a random one rgb = rand(200,200,3); % Convert it gray = 0.2989 * rgb(:,:,1) + 0.5870 * rgb(:,:,2) + 0.1140 * rgb(:,:,3); The directory structure in Matlab: 1. You can read files from a subdirectory, change directory, write a file in a subdirectory,…, in Matlab. Indeed, Matlab has a structure dir: listing = dir('name') returns attributes about name to an m‐by‐1 structure, where m is the number of files or folders in name. For example, a = dir(‘images’) will return the names of all the files and folders in subdirectory named “images” and for each file or folder, a has an entry with following structure: name date bytes isdir datenum So, to get the file or folder name of a(2), we use a(2).name 2. Please view http://blogs.mathworks.com/pick/2008/02/26/matlab‐basics‐getting‐a‐directory‐listing/ ...
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This note was uploaded on 01/16/2012 for the course MAD 4103 taught by Professor Li during the Spring '11 term at University of Central Florida.
- Spring '11