Resizing without squashing: Smart Scale in Paint
Smart Scale in Paint by Zaweba resizes a picture by removing or adding low importance seams, protecting a selection or skin tones so people keep their shape.
Ordinary resizing treats every part of a picture equally. Make a landscape photo narrower and everything in it gets thinner, including the people and the buildings. Smart Scale in Paint by Zaweba takes a different approach. It works out which parts of the picture matter least and removes or adds there, so the important parts keep their shape.
How seam carving works
Edit > Smart Scale uses seam carving. A seam is a line of pixels that runs from one edge of the picture to the other, one pixel wide, winding through the areas where little is going on: plain sky, an even wall, calm water. To make the picture narrower, Smart Scale removes the seams of least importance one after another. To make it wider, it adds seams in those same quiet areas.
The result is that a wide beach scene can be made narrower by squeezing the empty sand and sky while the people stay the same width. A square product photo can be made into a wide banner by stretching the plain background and leaving the product alone.
Smart Scale has an amount slider that mixes in normal scaling. At full strength you get pure seam carving. Turned down, part of the change comes from ordinary scaling. Mixing the two is often the most natural look, because pure seam carving pushed hard can leave odd joins, while a little normal scaling spread over everything hides them.
Protecting what matters
The method guesses what is important, and it is a good guesser, but it does not know that the small person in the corner is the point of the picture. So you can protect areas. Use the current selection or a saved selection as protection, and Smart Scale avoids cutting through it.
There is also an option to protect skin tones by colour range. That is valuable for people. Seam carving can otherwise squeeze a face or a body if the background around them is busy, and protecting skin keeps people looking like themselves.
Good uses for Smart Scale
Changing the shape of a photo for a different layout: a portrait shot needed as a landscape header, or a wide photo needed as a square post. Making room for text, by widening a quiet area of sky or wall. Removing gaps between subjects, by squeezing out the empty middle of a picture. Fitting a picture into a set size for a print or a web slot without cropping away the subject.
When to use something else
Smart Scale needs quiet areas to work with. On a picture that is busy all over, a crowd or a forest, there is nowhere unimportant to take seams from and the result can look broken. In those cases a crop, or Canvas Size with a fill, is the better answer. And for simply making a picture smaller in every direction, Image Size is the right tool.
Better results
Protect the subject with a selection every time; it costs a few seconds and saves a lot of fixing. Change size in moderate amounts. Look closely at straight lines, such as horizons, fences and building edges, since seams that cross them can make them kink. If they do, lower the amount slider or protect the line with the selection too.
What can go wrong
Faces squeezed because skin was not protected. Kinks in straight lines. Repeating patterns that become uneven. All of them are fixed the same way: undo, protect more, and ask for less change.
Smart Scale is one of those tools that feels a little like magic the first time, and with care it lets Paint by Zaweba reshape a photo without cropping away what you wanted to keep.
