Wavelets: Working with Images :: Using Wavelets (Wavelet Toolbox)

Wavelet Toolbox

Wavelets: Working with Images

This section provides additional information about working with images in the Wavelet Toolbox. It describes the types of supported images and how MATLAB represents them, as well as techniques for analyzing color images.

Understanding Images in MATLAB

The basic data structure in MATLAB is the rectangular matrix, an ordered set of real or complex elements. This object is naturally suited to the representation of images, which are real-valued, ordered sets of color or intensity data. (This toolbox does not support complex-valued images.)

The word pixel is derived from picture element and usually denotes a single dot on a computer display, or a single element in an image matrix. You can select a single pixel from an image matrix using normal matrix subscripting. For example,

```
I(2,15)
```

returns the value of the pixel at row 2 and column 15 of the image I. By default, MATLAB scales images to fill the display axes; therefore, an image pixel may use more than a single pixel on the screen.

Importing and Exporting Information from the Graphical Interface Indexed Images