need help in image processing

i would start by playing with the contrast. most of the dark bands look like they have very low intensity, so i would try thresholding the input values to 0 if they are below a low value (maybe 40) and otherwise set them to 255. you will have a black and white image and hopefully the bands will be very well defined

then you could try going down a number of pixel columns and counting the number of transitions between black and white. if you did this every 10 pixels or so you could average the number of transitions you count and round to get your final count

i'd be interested to see the output images from each step including the Sobel operator