How to store a pixel location in an array?

Suppose i'm scanning my image for pixels that match a criteria,

instead of storing the PIXEL itself, i want to put the X-coordinate and the Y-coordinate of the pixel into an array

if i were doing it in C, it would look something like int a[i][j]=(i,j);

Basically, i just need a way to store the X-and Y-coordinates in a single array so i can access them that way. is this possible? please suggest what i could do otherwise.

Answer 1

[Azzi Abdelmalek]

a=[1 2 3;4 5 6;7 8 9] % your array
[ii,jj]=find(a>4) % In this example the criteria is a>4, ii and jj are the coordinate
coordinate=[ii jj]

Answer 2

[Image Analyst]

binaryImage = yourImage == criteria;

That will give you a logical "map" of what pixels meet your criteria. That is most likely all you will need. You most probably won't need the actual row and column number, even though you think you do. For example, turn all pixels brighter than 110 to white (255)

binaryImage = yourImage > 110; % Find the pixels.
yourImage(binaryImage) = 255;  % Set them to 255

[pooja]

Sir, i need to know the pixel locations so i can keep some belonging to one intensity level and force the rest to go another intensity level.

to perform histogram equalization using bucket filling method.