Can someone explain how they are splitting the image here?
It takes the first 150 columns of image (first dimension in image being rows, second being columns, and third usually RGB). when you call a dimension by : you are selecting all elements along that axis. And calling a dimension by i:j select all the elements between i-th and j-th (including i and excluding j) along that dimension. It then multiplies all those selected values to 1.5 and clips the values to be between 0 and 255.
I don't understand how what each value represents, would someone be able to explain?
img_left[:,0:150,:] = np.clip(img_left[:,:150,:]*1.5,0, 255)