Image is kinda blurry compared to img2sixel

[ErrorNoInternet]

Images displayed by chafa are slightly blurrier than ones displayed by img2sixel (libsixel)
Also, the ones displayed by chafa are a few pixels shorter (in height) compared to the ones by img2sixel I think (not sure if that's actually the case or maybe it's just my eyes). Maybe that's why it's blurrier? See the image below:

And the original image:

Using Konsole 22.12.0

[hpjansson]

Hi! Thanks for filing the report.

You're right, it's blurrier. The reason is that Chafa internally handles dimensions as cell extents, not pixels. The image is scaled to fit a certain number of text cells exactly: When I first defined the API, I hadn't considered pixel-perfect graphics (originally it only did ANSI art).

I have ideas on how to fix it, but it requires some API finesse (e.g. how to align the image in the cell extent it occupies -- left, right, center). This issue seems like a good place to track the progress :-)

[hpjansson]

I've been working on extending my image library to allow simultaneous scaling and subpixel translation, which will fix the problem once it's done. Of couse it succumbed to feature creep (sRGB! Fast sRGB! More AVX! New tests and benchmarks! Even more AVX!), but it's getting there on my local branch. Arguments for image alignment are also being added (discussion in #140).