FontDatabase.h with its includes add up to quite a lot of code. In the
next commit, compiled GML files are going to need to access the
FontWeight enum, so let's allow them to do that without pulling in lots
of other things.
Also, change users to include FontWeight.h instead of FontDatabase.h
where appropriate.
This tag is required by the specification, but some encoders (at least
Krita) don't write it for images with a single strip.
The test file was generated by opening deflate.tiff in Krita and saving
it with the DEFLATE compression.
Type 2 <=> One-dimensional Group3, customized for TIFF
Type 3 <=> Two-dimensional Group3, uses the original 1D internally
Type 4 <=> Two-dimensional Group4
So let's clarify that this is not Group3 1D but the TIFF variant, which
is called `CCITTRLE` in libtiff. So let's stick with this name to avoid
confusion.
Images with a display mask ("stencil" as it's called in DPaint) add
an extra bitplane which acts as a mask. For now, at least skip it
properly. Later we should render masked pixels as transparent, but
this requires some refactoring.
SamplingFactors already has default initializers for its field,
so no need to have an explicit one for the first of the two fields.
No behavior change.
We now allow all subsampling factors where the subsampling factors
of follow-on components evenly decode the ones of the first component.
In practice, this allows YCCK 2111, CMYK 2112, and CMYK 2111.
Previously, we handled sampling factors as part of ycbcr_to_rgb().
That meant it worked ok for code paths that used YCbCr ("normal"
jpegs, and the YCC part of YCCK jpegs), but it didn't work for
example for the K channel in YCCK jpegs, nor for CMYK.
By making this a separate pass, it should now work for all cases.
It also makes it easier to support more subsampling arrangements
in the future, and to use something better than nearest neighbor
for upsampling subsampled blocks.
All the data is passed using the `Metadata` object, which has a
`main_tags` method. This method should be used when displaying only a
few main tags, for example to fill the property window of a file
manager. Another method returning the entire list of tags will be
implemented later on.
A bit faster:
```
N Min Max Median Avg Stddev
x 50 0.97179127 1.0031381 0.98313618 0.98407591 0.0092019442
+ 50 0.95996714 0.99507213 0.96965885 0.97242294 0.0095455053
Difference at 95.0% confidence
-0.011653 +/- 0.00372012
-1.18415% +/- 0.378032%
(Student's t, pooled s = 0.0093753)
```
According to ministat, a bit faster to render page 3 of 0000849.pdf:
```
N Min Max Median Avg Stddev
x 50 1.000875 1.0427601 1.0208509 1.0201902 0.01066116
+ 50 0.99707389 1.03614 1.0084391 1.0107864 0.010002724
Difference at 95.0% confidence
-0.00940384 +/- 0.0041018
-0.921773% +/- 0.402062%
(Student's t, pooled s = 0.0103372)
```
Reduces time spent rendering page 3 of 0000849.pdf from 1.45s to 1.32s
on my machine.
Also reduces the time to run Meta/test_pdf.py on 0000.zip
(without 0000849.pdf) from 58s to 55s.
Reduces time spent rendering page 3 of 0000849.pdf from 1.85s to 1.45s
on my machine.
As determined by running
time Build/lagom/bin/pdf --page 3 --render out.png \
~/Downloads/0000/0000849.pdf
a few times and eyeballing the min time.
Also reduces the time to run Meta/test_pdf.py on 0000.zip
(without 0000849.pdf) from 1m7s to 58s.
We refuse any image with a sample depth greater than 32, storing these
value as `u64` prevent any overflows. This is probably overkill as no
one in their right mind will use a 32 bits color table.
frame() still returns a regular RGB Bitmap (now lazily converted
from internal CMYK data), but JPEGImageDecoderPlugin now also
implements cmyk_frame().
