MATLAB: Generating multiple ROIs from a single image. (Automatic generation of ROI required)

Image Processing Toolboxroi generation

I have this code below which works fine, but it is time consuming.
Is there a better and faster solution possible?
if true im = imread('my_image.png'); I = single(rgb2gray(im))/255;
%getting height and width of image
width = size(im,2);
height = size(im,1);
k = 15;
x = randsample(height,k);
y = randsample(width,k);
sP = horzcat(x,y);
for i = 1:k
     if (((sP(i,1)+100) < height) &&  ((sP(i,2)+100) < width) &&  ((sP(i,1)-100) > 0) &&  ((sP(i,2)-100) > 0))
                x_min = sP(i,1)-100;
                x_max =sP(i,1) + 100;
                y_min = sP(i,2)-100;
                y_max = sP(i,2)+100;
                roi = im(x_min:x_max,y_min:y_max,:);
              imwrite(roi,['MYlocation' strcat(num2str(i) ,'_roi.png')],'png');
    elseif((((sP(i,1)+200) < height) || ((sP(i,1)- 200) > 0)) && (((sP(i,2)+200) < width) || ((sP(i,2)- 200) > 0)))
        if ((sP(i,1)+200) < height)
      x_min = sP(i,1);
      x_max = (sP(i,1)+200);
        elseif ((sP(i,1)- 200) > 0)
            x_min = sP(i,1)-200;
            x_max = sP(i,1);
         end
      if((sP(i,2)+200) < width)
        y_min = sP(i,2);
        y_max = (sP(i,2)+200);
      else
          y_min = (sP(i,2)- 200);
          y_max = sP(i,2);
      end
      roi = im(x_min:x_max,y_min:y_max,:);
      imwrite(roi,['MYlocation' strcat(num2str(i) ,'_roi.png')],'png');
         else
          continue; 
      end
  end
end

Best Answer

It's not time consuming on my computer - it's pretty fast.
Elapsed time is 0.675276 seconds.
And that even included an imshow() to see what I was saving. How long does it take for you?
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