www.gusucode.com > images 案例代码 matlab源码程序 > images/BasicImageImportProcessingAndExportExample.m

    %% Basic Image Import, Processing, and Export
% This example shows how to read an image into the workspace, adjust
% the contrast in the image, and then write the adjusted image to a file.
%% Step 1: Read and Display an Image
% Read an image into the workspace, using the |imread| command. The example
% reads one of the sample images included with the toolbox, an image of a
% young girl in a file named |pout.tif| , and stores it in an array
% named |I| . |imread| infers from the file that the graphics file format
% is Tagged Image File Format (TIFF).
I = imread('pout.tif');
%%
% Display the image, using the |imshow| function. You can also view an
% image in the Image Viewer app. The |imtool| function
% opens the Image Viewer app which presents an integrated environment for
% displaying images and performing some common image processing tasks. The
% Image Viewer app provides all the image display capabilities of
% |imshow| but also provides access to several other tools
% for navigating and exploring images, such as scroll bars, the Pixel
% Region tool, Image Information tool, and the Contrast Adjustment tool.
imshow(I)
%% Step 2: Check How the Image Appears in the Workspace
% Check how the |imread| function stores the image data in the workspace,
% using the |whos| command. You can also check the variable in the
% Workspace Browser. The |imread| function returns the image data in the
% variable |I| , which is a 291-by-240 element array of |uint8| data.
whos I
%% Step 3: Improve Image Contrast
% View the distribution of image pixel intensities. The image |pout.tif| is
% a somewhat low contrast image. To see the distribution of intensities in
% the image, create a histogram by calling the |imhist| function. (Precede
% the call to |imhist| with the figure command so that the histogram does
% not overwrite the display of the image |I| in the current figure window.)
% Notice how the histogram indicates that the intensity range of the image
% is rather narrow. The range does not cover the potential range of [0,
% 255], and is missing the high and low values that would result in good
% contrast.
figure
imhist(I)
%%
% Improve the contrast in an image, using the |histeq| function. Histogram
% equalization spreads the intensity values over the full range of the
% image. Display the image. (The toolbox includes several other functions
% that perform contrast adjustment, including |imadjust| and |adapthisteq|,
% and interactive tools such as the Adjust Contrast tool, available in the
% Image Viewer.)
I2 = histeq(I);
figure
imshow(I2)
%%
% Call the |imhist| function again to create a histogram of the equalized
% image |I2| . If you compare the two histograms, you can see that the
% histogram of |I2| is more spread out over the entire range than the
% histogram of |I| .
figure
imhist(I2)
%% Step 4: Write the Adjusted Image to a Disk File
% Write the newly adjusted image |I2| to a disk file, using the |imwrite|
% function. This example includes the filename extension |'.png'|  in the
% file name, so the |imwrite| function writes the image to a file in
% Portable Network Graphics (PNG) format, but you can specify other
% formats.
imwrite (I2, 'pout2.png');
%% Step 5: Check the Contents of the Newly Written File
% View what |imwrite| wrote to the disk file, using the |imfinfo| function.
% The |imfinfo| function returns information about the image in the file,
% such as its format, size, width, and height.
imfinfo('pout2.png')