Saturday, March 16, 2013
Using Photoshop for Stream Table Image Analysis
Yet another wonderful thing about the color-coded plastic media is the ability to analyze stream features over time. The colors tend to organize themselves into patterns based on where the water is flowing that correspond to areas of erosion, transport, and deposition. My hope is that I can use these colors to define active/abandoned channels in each time lapse frame - stacking frames will show how those channel patterns over time. But how to simplify the images? One of the challenges lies in the fact that the yellow sediment contains some red hues - a simple saturation boost would make the yellows pop out too much. So I grabbed a picture of the stream table and tried out some Photoshop filters and adjustments to simplify the image. I've put them into an animated gif to show the differences.
I've noticed that the smallest red grains tend to show up in areas of scouring, while the white and yellow are often the first to move and the first to be deposited. Some of these adjustments really help pull out the yellow and red. Now it's time to get a time-lapse sequence and try some time series analysis.