Figure 4.1: False color image plots for the first array. From top to bottom: red background with a logarithmic color scale, green background with a logarithmic color scale, red background with a rank color scale, green background with a rank color scale, rank of the average of logarithms of red and green foreground. In all of the images, we can see traces of a scratch towards the right of the images. Also, there is a pattern of horizontal stripes. In the bottom plot, we can see a gradient from left to right. The color scale determines how the feature intensity values are mapped to the range of colors. Often, the rank scale is more sensitive for the detection of patterns than the logarithmic or untransformed scales. Patterns or scratches such as seen here may affect the downstream analysis, but it is difficult to say from these plots alone how consequential they really are for the bottomline result.