**svd_gray_test**,
a MATLAB program which
calls svd_gray() to read a file containing a grayscale image and
uses the singular value decomposition (SVD) to
compute and display a series of low rank approximations to the image.

The computer code and data files described and made available on this web page are distributed under the GNU LGPL license.

svd_gray, a MATLAB program which reads a gray scale image, computes the Singular Value Decomposition (SVD), and constructs a series of low rank approximations to the image.

- svd_gray_test.m, calls all the tests.
- svd_gray_test.sh, runs all the tests.
- svd_gray_test.txt, the output file.

Approximations were made using 1, 2, 5, 10, 20, 40, and 80 optimal columns:

- casablanca.png, a gray-scale image from the movie "Casablanca".
- svd_gray_approximation_1.png
- svd_gray_approximation_2.png
- svd_gray_approximation_5.png
- svd_gray_approximation_10.png
- svd_gray_approximation_20.png
- svd_gray_approximation_40.png
- svd_gray_approximation_80.png