After dividing a 512*512 image into non overlapping two pixel blocks, why can't i perform operations on the pixel values? If i multiply a pixel value (163) with 5, it shows 255 everytime..what could be done to perform operations on the pixel values?

After dividing a 512*512 image into non overlapping two pixel blocks, why can't i perform operations on the pixel values?

If i multiply a pixel value (163) with 5, it shows 255 everytime..what could be done to perform operations on the pixel values?

Answer 1

[Munish Raj]

It is my understanding that you are not able to perform a multiplication operation (pixel*5) on individual pixels of your blocks. When you multiply your pixel by 5, it shows 255 every time.

This might be because the pixel values in MATLAB vary from 0 – 255 (0 being the minimum and 255 being the maximum).

When you try to modify a pixel to anything above 255, MATLAB will automatically keep the pixel at 255.

If your application requires you to scale a particular pixel by 5 times as compares to the other pixels,

you could scale all pixels down by a factor of 5 and then multiply the required pixel by 5.

I = imread('image_path');             %replace image  with your image path e.g.: C://users/documents/1,jpg
I=I/5;                     %scale down all pixels by 5

%perform your operations here
%
%
%

%all the pixels will be dim, except the pixels you multiply by 5.

Munish Raj

[Kiruba S]

Thank you sir