* quick hack
won't even compile
* works!
at a basic level, anyway
* start wiring up metadata
* metadata done
* add spng interlaced save
* start adding index support
* fix palette save
* Update libvips/foreign/spngsave.c
Co-authored-by: Kleis Auke Wolthuizen <github@kleisauke.nl>
* start adding low bit depth write
* add a warning for low bitdepth write
* small fixes
* add 1/2/4 bit write
adapted from the vips2tiff bit packer
* small polish
* note spngsave in changelog
* Update libvips/foreign/spngsave.c
Co-authored-by: Kleis Auke Wolthuizen <github@kleisauke.nl>
* Update libvips/foreign/spngsave.c
Co-authored-by: Kleis Auke Wolthuizen <github@kleisauke.nl>
* revise 8 and 16-bit PNG write rules
* cleanup
* remove unnecessary palette filter optimisation
since libspng already does this
* add xres/yres rounding
thanks klies
he commit message for your changes. Lines starting
* look for spng.pc and libspng.pc
It can be called either, frustratingly.
* fix PACKAGES_USED for spng .pc changes
Co-authored-by: Kleis Auke Wolthuizen <github@kleisauke.nl>
This patch makes "insert" issue minimise signals for inputs in sequential
mode. This can drop memory use in some programs, for example:
```python
import sys
import random
import pyvips
image = pyvips.Image.black(20000, 20000)
for filename in sys.argv[2:]:
tile = pyvips.Image.new_from_file(filename, access='sequential')
x = random.randint(0, image.width - tile.width)
y = random.randint(0, image.height - tile.height)
image = image.insert(tile, x, y)
image.write_to_file(sys.argv[1])
```
Before this patch:
```
$ for i in {0..1000}; do cp ~/pics/k2.jpg $i.jpg; done
$ /usr/bin/time -f %M:%e ../manyjoin.py ../x.jpg *.jpg
5456256:4.34
```
With this patch:
```
$ /usr/bin/time -f %M:%e ../manyjoin.py ../x.jpg *.jpg
2475324:3.38
```
tell buffer and target savers the file format
Currently, buffer and target savers are not told the format they should
write.
This is usually OK (the JPEG saver already knows it should write JPEG),
but some savers can write several formats, and these currently need an
extra parameter.
For example:
```ruby
buf = x.write_to_buffer ".bmp", format: "bmp"
```
The first ".bmp" gets libvips to pick magicksave, the second
`format:` param is necessary to tell magicksave to write BMP.
This patch adds stub subclasses so that the savers know the exact format. It also improves PPM save.
