frame_num = 1000;

img = imread( strcat( 'C:\Users\Ekaterina\Desktop\Ekaterina\ERASMUS MUNDUS\THESIS\fast camera\test the code\9525\',num2str(frame_num,'%07i'),'.png' ) );
img_double = im2double(img);
img_max = max(max(img_double));
img_min = max(min(img_double));
frame_write = (img_double - img_min)./(img_max - img_min);


imagesc(frame_write);