Creating a random dot pattern with increasing grayscale

Hi,

I am trying to numerically generate a dotted pattern made of dot of 2 pixels which are randomly distributed and save it as an image. I have tried

sz = 500;

Ah = rand(sz,sz);

imshow(Ah);

but I cannot control the size of the dots.

Answer 1

[Image Analyst]

Try this. Adapt parameters as needed.

% Define output image.
imageRows = 48;
imageColumns = 64;
grayImage = zeros(imageRows, imageColumns, 'uint8');
% Define dot parameters.
dotRows = 1;
dotColumns = 2;
maxDotBrightness = 255;
minDotBrightness = 120;
numDotsToBePlaced = 100;
numDotsPlacedSoFar = 0;
while numDotsPlacedSoFar < numDotsToBePlaced
    thisDotBrightness = uint8(minDotBrightness + (maxDotBrightness - minDotBrightness)  * rand);
    randomRow = randi([1, imageRows- dotRows-1], 1, 1);
    randomColumn = randi([1, imageColumns-dotColumns-1], 1, 1);
    grayImage(randomRow : randomRow + dotRows - 1, randomColumn:randomColumn+dotColumns-1) = thisDotBrightness;
    numDotsPlacedSoFar = numDotsPlacedSoFar + 1;
end
imshow(grayImage, [])
axis('on', 'image')
% impixelinfo; % Mouse around and see values
grid on;