Easy post-processing in Affinity Photo
This is the process I use in Affinity Photo v2 to enhance the stacked JPEG images from Seestar S30. I am confident that this will all work in the Pixel mode of the more recent free version of Affinity.
- In Affinity open the JPEG image stacked by your Seestar (or other camera).
- You may want to use menu option "Document/Rotate 90° clockwise" and then Ctrl-0 to see the image a bit larger.
- On the Layer menu select "New Live Filter Layer/Noise/Denoise..."
- In the resulting dialogue push both "Luminance" and "Colours" right up to 100%. Then close the dialogue (it can be reopened from the layers panel if necessary).
- On the Layer menu select "New Adjustment Layer/Brightness&Contrast...". In the resulting dialogue push both sliders to the right as far as you want.
- If some of the background is not black enough add another adjustment layer: "Curves". Pin the middle of the diagonal line and then just move the dark section down a little bit.
- If you rotated the image you may want to rotate back and perhaps crop, to taste.
- "File/Export..." to save in various formats. More info below.
In a demonstration I gave recently I then switched off the denoise filter from the layers panel so that the increased brightness and contrast revealed how noisy the original image really was.
The curves dialogue setting used in the example on the right:
Make the filter visible in the layers panel by clicking the arrow 1 (as shown below). The filter is switched off and on again by clicking the black spot 2 at the right of its layer. Dialogues can be made visible again for readjustment by clicking the icons in column 3.
Q: What's the difference between an adjustment and a filter?
A: An adjustment is something that can be done at every individual pixel without considering neighbouring pixels. A filter takes neighbouring pixels into account. If you think about it, denoising must consider what each pixel is doing in relation to its neighbours, so it must be a filter.
A portion of the original JPEG stacked by Seestar, shown here at full size:
The result of the process described on the left:
If you then switch off the denoise filter:
Save or Export?
"File/Save As..." will save in Affinity's own format, containing all the layer information. That will make files that can only be read by Affinity. For more general formats you need "File/Export...". Be aware that for PNG you will probably want 8 bits rather than the default 32-bit setting in the dialogue.