image_double, a MATLAB code which modifies an image file by doubling the number of rows and columns. When displayed, this should result in an image that appears twice as wide and high, with 4 times as many pixels.

In general, a better way to get a bigger picture is simply to use the original file, but increase the display size by stretching or rescaling. Here, we just want a simple way to make an image that will ``automatically'' display itself with doubled dimensions.

This doubling procedure may be repeated. The function image_decimate() will reverse the doubling operation.


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


image_double is available in a MATLAB version.

Related Data and Programs:

image_boundary, a MATLAB code which reports the pixels which form the boundary between the black and white regions of a simple image.

image_components, a MATLAB code which seeks the connected "nonzero" or "nonblack" components of an image or integer vector, array or 3d block.

image_contrast, a MATLAB code which applies image processing techniques to increase the contrast in an image.

image_decimate, a MATLAB code which ``compresses'' a file by deleting the even rows and columns.

image_denoise, a MATLAB code which applies image processing techniques to remove noise from an image.

image_diffuse, a MATLAB code which uses diffusion to smooth out an image.


image_edge, a MATLAB code which demonstrates a simple procedure for edge detection in images.

image_noise, MATLAB codes which add noise to an image.

image_quantization, a MATLAB code 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 codes which makes a grayscale version of an rgb image.

image_threshold, MATLAB codes 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.

Source Code:

Last revised on 03 February 2019.