move whatsnew to gh-pages
This commit is contained in:
John Cupitt
parent
806c7dc235
commit
3b4bb618c0
BIN
astronauts.png
BIN
astronauts.png
Binary file not shown.
|
Before Width: | Height: | Size: 938 KiB |
182
whats-new.md
182
whats-new.md
@ -1,182 +0,0 @@
|
||||
---
|
||||
title: What's new in 8.11
|
||||
---
|
||||
|
||||
libvips 8.11 is almost now out, so here's a quick overview of what's new. Check
|
||||
the [ChangeLog](https://github.com/libvips/libvips/blob/master/ChangeLog)
|
||||
if you need more details.
|
||||
|
||||
Credit to Zeranoe, DarthSim, Projkt-James, afontenot, 781545872, erdmann,
|
||||
kleisauke and others for their great work on this release.
|
||||
|
||||
[Lunaphore](https://www.lunaphore.ch/) kindly sponsored the development of
|
||||
the new JPEG2000 features, see below.
|
||||
|
||||
# Experimental JPEG-XL support
|
||||
|
||||
We've added perimental support for[JPEG-XL](https://jpeg.org/jpegxl/).
|
||||
This is a new iteration of the JPEG standard,
|
||||
currently in development. The Chrome web browser supports it
|
||||
behind a flag, and it looks like it might be enabled by default this autumn
|
||||
in Chrome 89.
|
||||
|
||||
There have been several attempts to replace JPEG with something better in the
|
||||
last few years. HEIC is perhaps the best known: it can compress files to
|
||||
about half the size of comparable JPEGs and supports a range of useful
|
||||
features like animations, transparency and lossless
|
||||
compression. Unfortunately, it has some patent issues which may limit its
|
||||
usefulness.
|
||||
|
||||
AVIF is rather like HEIC, but has no patents attached to it. Sadly the
|
||||
available load and save libraries are extremely slow.
|
||||
|
||||
JPEG-XL looks like it might avoid all these problems: it offers the same great
|
||||
compression and useful features as HEIC and AVIF, but has no problems with
|
||||
patents, and is fast enough for practical use.
|
||||
|
||||
I made a sample image. You'll need to zoom in to check details:
|
||||
|
||||
|
||||
|
||||
Compression and decompression is quite a bit quicker than HEIC:
|
||||
|
||||
```
|
||||
$ time vips copy astronauts.png x.jxl
|
||||
real 0m0.218s
|
||||
user 0m0.291s
|
||||
sys 0m0.204s
|
||||
|
||||
$ time vips copy astronauts.png x.heic
|
||||
real 0m0.413s
|
||||
user 0m1.273s
|
||||
sys 0m0.048s
|
||||
```
|
||||
|
||||
JPEG-XL is still a little immature, so it's not enabled by default in
|
||||
libvips 8.11. Hopefully the missing features (metadata, progressive encode
|
||||
and decode, animation, etc.) will arrive soon, and the remaining bugs will
|
||||
be squeezed out.
|
||||
|
||||
# Thread recycling
|
||||
|
||||
We've revamped the libvips threading system.
|
||||
The new implementation uses a [GLib thread
|
||||
pool](https://developer.gnome.org/glib/stable/glib-Thread-Pools.html)
|
||||
to provide a single set of threads for the whole of libvips. This means
|
||||
threads get reused rather then being constantly created and destroyed.
|
||||
|
||||
This was originally intended for WebAssembly but it turned out to be useful
|
||||
for native environments as well. Relative speed-ups are varying between ~4%
|
||||
and ~15% compared to the previous implementation. Especially for short-lived
|
||||
pipelines and long-running processes, a performance improvement can be observed.
|
||||
|
||||
# Loadable modules for some dependencies
|
||||
|
||||
libvips now supports building OpenSlide, libheif, Poppler and libMagick
|
||||
as dynamically loadable modules. This makes it easier for distributions to
|
||||
provide separate (optional) packages for these dependencies, making the core
|
||||
package much slimmer and thus reducing the attack surface. Distributing
|
||||
separate packages could also help to comply with GPL licensing (“mere
|
||||
aggregation” clause) or patent-encumbered software.
|
||||
|
||||
[GModule](https://developer.gnome.org/glib/stable/glib-Dynamic-Loading-of-Modules.html)
|
||||
is used to accomplish this in a portable way. We already had a simple plugin
|
||||
system based on this, but the build part was not yet implemented.
|
||||
|
||||
These loadable modules are built automatically when GModule is supported,
|
||||
which should be at least Linux, Windows and macOS. It can be disabled by
|
||||
passing `--disable-modules` while configuring libvips.
|
||||
|
||||
# Full-colour text rendering
|
||||
|
||||
The libvips `text` operator was designed a while ago, when fonts were still
|
||||
black and white. It outputs a one-band mask image which you then process with
|
||||
the other libvips operations to do things like rendering text on an image.
|
||||
|
||||
Many fonts, especially emoji fonts, now have full-colour SVG characters.
|
||||
There's a new `rgba` flag to `text` to enable colour rendering. For example:
|
||||
|
||||
```
|
||||
$ vips text x.png "😀<span foreground='red'>red</span><span background='cyan'>blue</span>" --dpi 300 --rgba
|
||||
```
|
||||
|
||||
Makes this:
|
||||
|
||||
|
||||
|
||||
You can then use `composite` to render these text RGBA images on to another
|
||||
image.
|
||||
|
||||
# JPEG2000 support
|
||||
|
||||
Thanks to generous sponsorship from Lunaphore, we've added support for the
|
||||
(now rather elderly) JPEG2000 format.
|
||||
|
||||
The `jp2kload` and `jp2ksave` operations support all the file format
|
||||
features: shrink-on-load, 8-, 16- and 32-bit data, any number of
|
||||
image bands, tiled images, YCC colourspace, lossless compression, and
|
||||
optional chroma subsampling. The lossy compression profile (controlled
|
||||
by a `Q` parameter) is derived from the [British Museum's JPEG2000
|
||||
recommendations](https://purl.pt/24107/1/iPres2013_PDF/An%20Analysis%20of%20Contemporary%20JPEG2000%20Codecs%20for%20Image%20Format%20Migration.pdf).
|
||||
|
||||
We've also added support for JPEG2000 as a codec for TIFF load and save. This
|
||||
means you can now directly load and save some popular slide image formats.
|
||||
This should be useful for people in the medical imaging community.
|
||||
|
||||
It's very easy to use -- for example:
|
||||
|
||||
```
|
||||
$ vips copy k2.jpg x.tif[compression=jp2k,Q=90,tile]
|
||||
$ vips copy k2.jpg x.tif[compression=jp2k,lossless]
|
||||
```
|
||||
|
||||
# C++ API improments
|
||||
|
||||
We've spent some time improving the C++ API.
|
||||
|
||||
We now use [doxygen](https://www.doxygen.nl) to generate C++ API docs
|
||||
automatically, and we've written a set of API comments. Hopefully the [new
|
||||
documentation](link-to-cpp-docs) should be a big improvement.
|
||||
|
||||
There are a couple of functional improvements too. There's support for
|
||||
`VipsInterpolate`, `guint64` and a new constructor,
|
||||
`VImage::new_from_memory_steal`, which can save a copy operation.
|
||||
|
||||
# Minor improvements
|
||||
|
||||
- The `perlin`, `worley` and `gaussnoise` operators have a new `seed`
|
||||
parameter to set the seed for their random number generator.
|
||||
|
||||
- The `rank` operator has a new path for large windows on 8-bit images. It can
|
||||
be up to 20 times faster in some cases.
|
||||
|
||||
- Image histograms on large images now use `double` values. Previously,
|
||||
we were limited to images with under 2^32 pixels.
|
||||
|
||||
- There's a new `black_point_compensation` for colour operations involving
|
||||
ICC profiles, and detection of bad profiles and fallback to default
|
||||
profiles is much better.
|
||||
|
||||
- The loaders and savers for PDFium, OpenSlide, vips, NIfTI, and FITS have
|
||||
been moved to the new libvips IO framework.
|
||||
|
||||
- `vipsthumbnail` can now load and save to and from stdin and stdout.
|
||||
|
||||
- PNG save selects between 8- and 16-bit output more intelligently, and
|
||||
supports background colour as metadata.
|
||||
|
||||
- We've switched GIF load to the excellent libnsgif library, and libvips
|
||||
embeds the library code.
|
||||
|
||||
- `tiffsave` can write premultipled alpha.
|
||||
|
||||
- PDFium support has been revised. It should now build very simply, and ought
|
||||
to be much faster in threaded applications.
|
||||
|
||||
- We've fixed a range of reference leaks in the mosaicing package, and we
|
||||
now run the leak checker as part of CI.
|
||||
|
||||
As usual,
|
||||
the [ChangeLog](https://github.com/libvips/libvips/blob/master/ChangeLog)
|
||||
has more details, if you're interested.
|
||||
|
||||
Loading…
Reference in New Issue
Block a user