Unexpected Feature: Vectorize a Bitmap Image Directly in Publisher

[loukash]

Believe it or not, a rudimentary vectorizer has been included with Affinity from the very launch of Publisher 1!
Before you get too excited though: it only works on images with transparency, for example 1-bit images with alpha channel.
But hey, better than nothing, right?

1. Place your image into a Publisher document, the more pixels the original image has, the better
2. Select the image and click the Edit Wrap Outline button in the main toolbar
3. Copy
4. Paste = Curves object: there's your image (roughly) vectorized, traced based on the transparency outline
5. Apply fill and stroke as you see fit
6. Optionally convert all the sharp nodes to smooth or smart nodes to make it appear less jagged, clean up as you see fit

Tested in APu v1.10.6 Mac and APu v2.0.3 iPad.

[loukash]

Works perfectly for vectorizing bitmap QR codes:

If the image doesn't have transparency yet, all you need to do is:

1. Place the QR code image in Publisher and select it with the Move tool
2. Context toolbar > Edit Image
3. Switch the opened image to the Photo persona
4. Flood Select tool > Contiguous: off > click the white background
5. Delete (optionally enable Transparent Background to check if all white pixels are gone)
6. Save (if PNG) or export as PNG (if JPEG, then replace the JPEG in the other afpub)
7. proceed with Wrap Outline as above

[NotMyFault]

Really nice catch. 👌👍👍👍

[NotMyFault]

Remember, you can convert any color to transparent with help of blend ranges.

More complex color transformations are possible with Chanel mixer or Procedural Texture filter.

Use posterize or gradient map for multi-pass tracing specific color ranges.

The new hue/luminosity live filter mask come handy.

[NotMyFault]

Does it generate 2-4 nodes per pixel - at every pixel edge in principle? (No opportunity to try it on my own today)

[loukash]

8 hours ago, NotMyFault said:

Remember, you can convert any color to transparent with help of […]

Yep, it opens quite a few possibilities, for instance by using some clever APh macros.

8 hours ago, NotMyFault said:

Does it generate 2-4 nodes per pixel - at every pixel edge in principle?

Something like that, as it seems.
^ Actually strike that, it's vice versa: more like a node per 8 pixels or so. Hence the jagged edges. Because generally that's "good enough" for text wrap, isn't it.

But before posting, I did a few tests to figure out what can make a difference. In the end it boils down to the sheer amount of pixels. More is more.
But… the more pixels, the more nodes. The more nodes, the more… troubles. There were a bunch of crashes and spin dumps along the way.

Edited January 25, 2023 by loukash
see strikethrough

[debraspicher]

2 hours ago, loukash said:

Believe it or not, a rudimentary vectorizer has been included with Affinity from the very launch of Publisher 1!
Before you get too excited though: it only works on images with transparency, for example 1-bit images with alpha channel.

[loukash]

43 minutes ago, NotMyFault said:

color to transparent with help of blend ranges

That doesn't work non-destructively in place. The image/pixel layer must be flattened with "real" transparency.
Also, the "absolute pixel grid" bug is an issue. Hence my workflow via Edit Image in a separate document, i.e. without any potential misalignment in the existing layout.

[debraspicher]

It has a million points to it, but it works-ish.

 

Paste into Designer (as curves). mmm 8-bit.

[loukash]

11 minutes ago, debraspicher said:

It has a million points to it

Straight lines are relatively easy to clean up, simply select all nodes inbetween two corners with the node-lasso and delete them.
To clean up round curves, it would need a quick method to select e.g. every 2nd node, delete the "steps", then convert the rest to smooth.

[loukash]

Here an example how to quickly vectorize a part of a photo – i.e. a pixel selection – in place:

Yeah, it's gonna be jagged. Get over it. That's jazz.  

[loukash]

To smooth the jagged edges, go to Designer persona and apply multiple steps of the following until you're satisfied with the result:

1. select all nodes > apply Corner Tool > Rounded > ~20 px (or about 2 mm @ 300 dpi) > Bake Appearance
2. select all nodes > click the Smooth Curve button a few times
3. select all nodes > click Convert: Sharp button
4. repeat steps 1 > 2 > 3 > etc. > 1 > 2
5. optionally apply Contour Tool or similar to your liking

Works surprisingly well within a minute or so.

Black is the initial jagged "million-nodes" vectorization of the hidden pixel layer, red overlay is a smoothed copy using several passes of the above workflow:

Not all that shabby, huh?  

[loukash]

Aaand vice versa, using the Edit Wrap Outline you can create fake pseudo-bitmap vector shapes of smooth curves!  

[loukash]

Tracing some "vector" brushes:

The trick: rasterize them first but avoid too many semi-transparent pixels. Fake "1-bit" images without antialiasing work best for tracing.

And again: the bigger the better.
Make sure your canvas is thousands of pixels wide for tracing. Heck, try ten thousands! (Save early, save often! )

[Glock]

7 hours ago, loukash said:

To smooth the jagged edges, go to Designer persona and apply multiple steps of the following until you're satisfied with the result:

1. select all nodes > apply Corner Tool > Rounded > ~20 px (or about 2 mm @ 300 dpi) > Bake Appearance
2. select all nodes > click the Smooth Curve button a few times
3. select all nodes > click Convert: Sharp button
4. repeat steps 1 > 2 > 3 > etc. > 1 > 2
5. optionally apply Contour Tool or similar to your liking

Works surprisingly well within a minute or so.

Black is the initial jagged "million-nodes" vectorization of the hidden pixel layer, red overlay is a smoothed copy using several passes of the above workflow:

Not all that shabby, huh?  

NO…Not at all…. I think I could totally live with that in 90% of my applications of the technique….

[prophet]

Brilliant! The perfectionist in me will want to go in a tweak all the little crevices, but this technique is a great starting point.

I think it also proves the capability for auto-trace already exists in Affinity, just needs some polish to bring it up to the "full tool/feature" level.

[Bryan Rieger]

I think this thread perfectly illustrates how one person's bug is another person's feature. Personally, I cringe every time I have to use the text wrap alpha feature in Publisher as I always end up having to go and delete 99% of the nodes and then redraw the shape (incl. curves) with a more reasonable node count which then allows me to tweak the shape to get the wrapping to work better. I'm always amazed at @loukash's ability to find endless (and ingenious) workarounds in the Affinity suite.

Hopefully we see improvements to both auto-trace tool and node/geometry clean-up tools in the not-too-distant future. 🤞