How to get 1% of the image?

After I load a image, how do we get the 1% of the image?

Answer 1

[Stalin Samuel]

A = imread('ngc6543a.jpg');
n =size(A,2)
Im_1per = A(:,1:round(n*0.01))%here 0.01 states that 1 % and it can be varied from 0.01 to 1.0
imshow(Im_1per)

[Image Analyst]

This is one percent of the columns, not of the whole image. Anyway you didn't say your criteria for which 1% of the image to pick. What are the chances you wanted the left-most 1%? Probably not very high. Post your image and say what 1% of the pixels you're thinking of.

[Jason]

What about left-up-most or random 1% of image? How to deal with this two situations?

[Image Analyst]

Sure, you could do that using indexing or randperm(), but what do you need to do to accomplish your task? What is your task, such that you need 1% of the pixels for something? What are you going to do with them once you have them, wherever they might be?

[Jason]

Could you write some code about that.

I am going to produce some percentage of a image, then insert this percentage of a image to the original image, using LSB.

[Jason]

I think randperm(n) could not work since how can we know the n. If we know n is 200. but pixel is not from 1-200? for example, pixel is 1, 3, 4, 200. But randperm(n) will produce like [3, 1, 2, 4, ...., 200, 199]