function to decrease image size

function [y] = ImageDecrease(i,n)
y=imresize(i,n);
size(y)
end

I need to create a function to decrease the image size. Ex. image size is 512px x 512px and if n=4 the size of image has to be 64x64 (the i parameter is the image)

This function doesnt work bc if scale is >1 it increases the image..

Answer 1

[Image Analyst]

I know it sounds obvious, so you've probably already done it by now, but did you try inverting the number:

function outputImage = ImageDecrease(inputImage, n)
[rows, columns, numberOfColorChannels] = size(inputImage);
fprintf('Input image has %d rows, %d columns, and %d color channels',rows, columns, numberOfColorChannels)
outputImage = imresize(inputImage, 1/n);
[rows, columns, numberOfColorChannels] = size(outputImage);
fprintf('Output image has %d rows, %d columns, and %d color channels',rows, columns, numberOfColorChannels)
end

[Altina Rexha]

THis isnt working, i think its a bad idea to use imresize. bc i cant get the output i want

[Image Analyst]

It DOES work. And using imresize is not a bad idea.

rgbImage = imread('Peppers.png');
subplot(2, 1, 1);
imshow(rgbImage);
axis('on', 'image');
outputImage = ImageDecrease(rgbImage, 4);
subplot(2, 1, 2);
imshow(outputImage);
axis('on', 'image');

function outputImage = ImageDecrease(inputImage, n)
[rows, columns, numberOfColorChannels] = size(inputImage);
fprintf('Input image has %d rows, %d columns, and %d color channels',rows, columns, numberOfColorChannels)
outputImage = imresize(inputImage, 1/n);
[rows, columns, numberOfColorChannels] = size(outputImage);
fprintf('Output image has %d rows, %d columns, and %d color channels',rows, columns, numberOfColorChannels)
end

Note on the axes how the number of colums goes from 512 to 128, indicating a reduction by a factor of 4.

You can also pass in the exact number of rows and columns you want, if you prefer that way.

outputImage = imresize(inputImage, [123, 456]); % Make 123 rows by 456 columns.

[Altina Rexha]

THank you it helped!!!