~enopatch

Recent activity

Re: Trying to understand imv's anti-aliasing. Can I switch this off? 4 months ago

From Jaime to ~exec64/imv-devel

On Sat, 15 Jan 2022 at 14:30, Harry Jeffery <me@harry.pm> wrote:
> Hi Jaime,

Hi Harry,

> I think you may be seeing the effects of the upscaling_method option. It
> affects images are scaled up by imv. 'linear' does smooth interpolation,
> and is the default, 'nearest_neighbour' will pick the value of the
> closest pixel which is what you'd want for pixel art.

That's exactly what it is. I now understand that what I thought was
anti-aliasing is actually the "linear" texture magnification function
(i.e. GL_TEXTURE_MAG_FILTER defaults to GL_LINEAR). I have now added:

Trying to understand imv's anti-aliasing. Can I switch this off? 4 months ago

From Jaime to ~exec64/imv-devel

Hi.

I'm trying imv (4.2.0) on debian stable (bullseye) and imv *appears*
to be performing some kind of anti-aliasing or "image smoothing". I
have come to this conclusion because I have a png with rendered text
and when I view that image in imv, the rendered text appears smoothed,
whereas when I view that same png in sxiv, the rendered text appears
either smooth or jagged depending on how I toggle sxiv's anti-aliasing
(using the "a" key). I have also had a quick dig through sxiv's source
and I've found where sxiv sets an anti-alias toggle on its underlying
rendering library:

https://github.com/muennich/sxiv/blob/master/image.c#L722