I finished the Crab Nebula with surprising results. It was easier than expected to turn different color filters into something that fits well as one. I used four color filters—clear, blue, red, and green color filters.
I changed each layer mode to screen. In the end, I duplicated each color filter, making a total of 11 layers that include the Visible layer, the Clear median Blur, and the High Pass filter!
Median blur is used to calculate the neighboring pixels' median, affecting the image's edges and corners. The median blur involves a radius, a neighborhood, and percentiles. I set the radius at 3 to increase the blur while setting the percentile and alpha percentile at 50 to make the tone of the image a balanced brightness while becoming more blurred. Alpha percentile works to achieve this balance by becoming more transparent.
The high pass filter "filters high essential details, and larger scale gradients are removed" (Gimp). Standard deviation, contrast, and clipping are adjusted. Increasing the standard deviation allows more details to be accounted for.
I was happy with this final image because I could clearly see the interaction of each color filter in the final product. A lot of the previous noise had been minimized to the extent that the image's primary focus was highlighted.
My favorite part about the results is the Crab Nebula appearing behind the stars rather than in front. I see the stars popping out at me, but the focus still lies in the colorful nebula.
I would prefer my image to be less grainy, even though it is suitable for a first try.
Image shows settings for Median Blur (Screenshot Creds: Sofia)
Image is the final product of my Crab Nebula project (Photo Creds: Sofia Laboy).