Revise premultiply

it wasn't really necessary, and it was rather slow

so we work on older libtiffs

allow this case:

vipsthumbnail k2.jpg --export-profile cmyk

for an image with no embedded pro...

Co-authored-by: Kleis Auke Wolthuizen <[email protected]>

Add tiff zstd predictor support

the enums were mixed up, thanks Adios

see https://github.com/libvips/libvips/issues/2128

to linnsgif, trying to find the GIF decode bug

though unfortunately libnsgif seems to have broken DISPOSE_PREVIOUS
handling again

and remove the old giflib loader

for compat in thumbnail behaviour

we actually test vipsthumbnail --linear on an RGBA image, which should
catch everything, hopefully

We were not detecting division by zero carefully enough, nor clipping
the alpha range sufficient...

Compress fallback colour profiles with zlib (zopfli, via pigz)

Reduces binary size by 580KB, ~17% at -O2

Set minimum glib-2.0 dependency version of 2.40 (March 2014)

this could cause crashes with very wide images, see:

https://github.com/libvips/libvips/issues/...

this could cause crashes with very wide images, see:

https://github.com/libvips/libvips/issues/...

fix the nan-avoidance code in mapim

see https://github.com/libvips/libvips/issues/2111

to steer people towards discussions

Bugs only, now we're using "discussions"

set pngsave default filter to none for palette images, since they usually
have low local correla...

and fix some small fits loading issues

see https://github.com/libvips/libvips/issues/1987

see https://github.com/libvips/libvips/issues/1987

Migrate from Travis CI to GitHub Actions

see https://github.com/libvips/libvips/issues/1987

svgload: remove was-deprecated, now-removed librsvg-features.h include

librsvg >= 2.40.3 includes it for you

librsvg >= 2.51.0 removes it entirely

and run the libvips leak test in CI

introduced recently

introduced a few days ago

introduced in https://github.com/libvips/libvips/commit/d8ed630d77c21a994e15939ccd148fcff9e423f2

and some more tests

to try to pin down the memleak

since images with more than 2*32 pixels will overflow a uint accumulator

thanks @erdmann

see h...

We were not avoiding NaN in float transform images, leading to segvs in
some cases.

Thanks afon...

Update URLs to HTTPS

so you can rewind most sources after reading (though not pipes)

see eg. https://github.com/libvips/libvips/issues/1964

pngsave was just using the image format to decide whether to save as 8
or 16 bit PNG. With this ...

heifsave: add option to control chroma subsampling

Defaults to no subsampling when Q>90 for consistency with jpegsave.

Deprecate VipsForeignJpegSu...

around 10x faster for 20x20 windows, the same speed for 3x3

Adapt test suite for AVIF support

and add some extra dbg to print profile properties

see https://github.com/libvips/libvips/issue...

+ include missing dependencies and build without magick.

Since the one provided by Ubuntu 20.04 does not depend on aom.

Saves a few bytes since the software version comment is no longer included in the hdlr box.

Reduces the size of the image by 6 kB.

Do a speculative spng_get_trns() in header read to force all chunks to
be parsed.

Thanks randy4...