Affinity Photo - convert to hard black/white, suggested workflow

[Lindsay Wilson]

I'd be grateful for suggestions on how to replicate the workflow I currently have with Photoshop for processing these images. I do a lot of laser engraving work, and for that I need crisp black/white bitmaps which I can trace (in Inkscape) to produce a vector file. Input image is e.g. a photo of a woodcut engraving, an ink sketch etc. In Photoshop, I first change the mode to grayscale, then use the brightness/contrast dialog with "Use Legacy" ticked, maximum contrast, and adjust the brightness to get the desired amount of edge detail. Then obviously touch up the final image manually.

This process has worked great, but I'm trying to find a way to replicate it in Affinity Photo.

The brightness/contrast adjustment doesn't have something comparable to the "legacy" option. So if I crank contrast up to 100, it doesn't give dead black/whites. Is there any way of doing this?

I finally tried using the posterise adjustment with 2 colors, which sort of does the trick, but I can't adjust the "threshold" like I could by adjusting the brightness slider.

On a separate note, Photoshop has a very useful filter called Median, under noise reduction. When this is applied to a black/white image, it sort of smooths out the edges, which makes tracing a lot better. Anything like this in Affinity?

[RichardMH]

You've tried the Threshold adjustment? Curves set to Gray does something similar with maybe a bit more control. There is a median blur filter (live and legacy)

[Lindsay Wilson]

@RichardMH Now I feel like an idiot - I never even noticed that, works perfectly! And the median blur filter as well. Thank you so much for the tips - I should really sit down and just go through every adjustment and filter to see what's available 😂