Remove Even Rows and Columns From Image

**IMAGE_DECIMATE**
is a MATLAB program which
``decimates'' an image by removing the even rows and columns,
resulting in a file that is about 1/4 the size of the original.

Modifying an image in this way is a very crude method of compression. However, it does suggest how much redundant information exists in a typical image file.

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

**IMAGE_DECIMATE** is available in
a MATLAB version.

IMAGE_COMPONENTS, a MATLAB library which seeks the connected "nonzero" or "nonblack" components of an image or integer vector, array or 3D block.

IMAGE_CONTRAST, a MATLAB program which applies image processing techniques to increase the contrast in an image.

IMAGE_DENOISE, a MATLAB library which applies image processing techniques to remove noise from an image.

IMAGE_DENOISE_SPMD, a MATLAB program which demonstrates the SPMD parallel programming feature for image operations; the client reads an image, the workers process portions of it, and the client assembles and displays the results.

IMAGE_DIFFUSE, a MATLAB library which uses diffusion to smooth out an image.

IMAGE_DOUBLE, a MATLAB library which doubles the height and width of an image by repeating each row and column.

IMAGE_EDGE, a MATLAB library which demonstrates a simple procedure for edge detection in images.

IMAGE_MATCH_GENETIC, a MATLAB program which tries to match a 256x256 JPEG image by blending 32 colored rectangles, using ideas from genetic algorithms, based on an example by Nick Berry.

IMAGE_NOISE, MATLAB programs which add noise to an image.

IMAGE_QUANTIZATION, a MATLAB library which demonstrates how the KMEANS algorithm can be used to reduce the number of colors or shades of gray in an image.

IMAGE_RGB_TO_GRAY, MATLAB programs which makes a grayscale version of an RGB image.

IMAGE_THRESHOLD, MATLAB programs which make a black and white version of a grayscale image by setting all pixels below or above a threshold value to black or white.

- image_decimate_gray.m, decimates a grayscale image.
- timestamp.m, prints the YMDHMS date as a timestamp.

- image_decimate_test.m, calls all the tests.
- image_decimate_gray_test.m, tests image_decimate_gray().
- image_decimate_test_output.txt, the output file.

**casablanca** is a grayscale image from a movie.

- casablanca.pgm, the original image.
- casablanca.png, the original image.
- casablanca2.pgm, the image after 1 decimation.
- casablanca2.png, the image after 1 decimation.
- casablanca4.pgm, the image after 2 decimations.
- casablanca4.png, the image after 2 decimations.
- casablanca8.pgm, the image after 3 decimations.
- casablanca8.png, the image after 3 decimations.
- casablanca16.pgm, the image after 4 decimations.
- casablanca16.png, the image after 4 decimations.
- casablanca32.pgm, the image after 5 decimations.
- casablanca32.png, the image after 5 decimations.

You can go up one level to the MATLAB source codes.