Graphics

Reading a Graphics Image

The function imread reads an image from any supported graphics image file in any of the supported bit depths. Most of the images that you will read are 8-bit. When these are read into memory, MATLAB stores them as class uint8. The main exception to this rule is that MATLAB supports 16-bit data for PNG and TIFF images. If you read a 16-bit PNG or TIFF image, it is stored as class uint16.

Note    For indexed images, imread always reads the colormap into an array of class double, even though the image array itself can be of class uint8 or uint16.

The following statement reads the image ngc6543a.jpg into the workspace variable RGB and then displays the image using the image function.

• RGB = imread('ngc6543a.jpg');
  image(RGB)
  

You can write (save) image data using the imwrite function. The statements

• load clown % An image that is included with MATLAB
  imwrite(X,map,'clown.bmp')
  

create a BMP file containing the clown image.

Reading, Writing, and Querying Graphics Image Files

Writing a Graphics Image

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