The process of identifying samples is similar to the process of
learning; with the exception that concentration is unknown and
will be predicted from the database of learnt images. First, the user
must take a photo of the unknown sample in the same conditions
as the learnt calibration images using the same closed lightbox
described earlier. The sample pixels are automatically evaluated
in the same manner, by cropping to the central 300 300 pixel
region and calculating the average color for red, green and blue
over the cropped pixels. From the red, green and blue values, we
can calculate the hue, saturation, brightness and gray