Question

what is patch extraction in matlab?

Answer 1

Image patches mean sub images. When an image is divided into disjoint or overlapping sub-parts, these sub-parts are called patches
of that image. In image pre-processing, it is useful in feature extraction. For example, a 100X100 image can be divided into ten
10X10 patches.

In MATLAB, every digital image is considered as a matrix with defined maximum number of rows and columns. The 100X100 image is a
matrix of 100 rows and 100 columns. When this matrix is divided into sub matrices, each sub matrix is termed as a patch of the
original. The code for dividing a 100X100 image into the first 10X10 patch would be:

Patch1 = full_image (1:10, 1:10);