My first test is about modifying a picture of a grass seed pod against a dark jacket under flat natural light. The objective is to obliterate the detail of the jacket to pure black and then bring out the maximum detail of the seed pod. I am used to do this with the Photoshop “Levels” tool, so I am really comparing GIMP’s “Levels Tool” against Photoshop’s Levels adjustment layer. First thing is starting GIMP from the Windows 10 “All Apps” menu. That was easy after a flawless almost fully automatic install. One click of the icon brings up the default GIMP screen. The one annoying thing is that the tools and option docking screens are separate and scattered over the screen. To avoid the confusion of the background software applications showing through, I chose to run GIMP in “Single Window Mode” (To see the detail in the image on the left, and enlarge it, click on it. When you are done, hit the backspace key on your keyboard or use the “return” link above the enlarged picture)
The next step is almost self explanatory, as in File – Open – Select Directory – Select the JPG file. The file loads and displays in the centre panel. Notice the detail in the almost black fuzzy jacket. The individual cloth loops show, and the seed pod colour is a bit flat.
Now we select from the top menu “Colors”. Here you will find the colour adjustment tools for photography. I select the “Levels” tool, which allows me to set the black and white cut-off points, and allows me to give more “weight” to the light or dark area of the remaining histogram.
This picture explains what happens with the sliders on the Levels tool. You can really see the dramatic results in the black background, and the “livening-up” of the seed pod. By moving the black slider at the bottom of the histogram to the right, all the dark colours left of the slider become pure black, obliterating the detail in the fuzzy jacket. On the very right of the histogram there are virtually no light colours, so we can slide the white slider to the left to the point where the first light colours register on the histogram. By sliding the middle slider to the left we lighten mainly the seed pod and adjust it to get maximum detail in the mid-tones.
One peculiarity with GIMP is that “Save As” option in the “File” menu, does not give you the usual photographic format options, such as JPG, JPEG, TIFF, GIF etc. You have to select “Export As”. Below are the full JPG files if you want to compare the before and after in detail.
So far I am quite impressed.