If the comment doesn't UTF-8 validate, leave valid UTF-8 at the
beginning intact. Also fix character range comparison to use guchar
instead of gchar
(cherry picked from commit f7413d70dd)
... in JPEG export.
Same as the WebP export, which is quite similar (8-bit max format), when
no profile was explicitly set, we want to convert any data from storage
format to non-linear (unlike when exporting high bit depth formats, such
as TIFF).
We only make an exception for 8-bit linear. This commit adds this
exception.
(cherry picked from commit 0461022198)
GIMP should not convert assigned profile to sRGB just because we stored
as linear on the XCF. In other words, we should not look at the image
precision to decide whether to export as linear (previously only 8-bit
linear images), but at the profile TRC. There are basically 3 cases:
(1) We don't save a profile, then convert to sRGB whatever the source
precision (because readers would assume sRGB for a no-profile jpeg).
(2) We save the default profiles: convert to sRGB because it's usually
a better choice for 8-bit formats and even working at 32-bit float
*linear* doesn't mean you want to export as 8-bit int *linear*. As the
image creator made no explicit export choice, we make an acceptable
default one.
(3) We save an explicitly assigned profile: keep the profile TRC, don't
convert!
Note that this apparently won't work perfectly right now, as GIMP
replaces the original TRC with the linear default TRC when converting to
linear. So the expected TRC is lost in such case when you have not
explicitly reset the correct profile. Yet this is on GIMP side and this
part of the issue should be fixed with the space invasion merge. For
now, this is how the plug-in should work.
This is based on my late discussion with Ell. Please everyone, and Ell
especially, review! :-)
... linear itself AND if we export the profile.
In most cases we want to save 8-bit image formats (here JPEG) as
non-linear, even though the work image may have been linear itself (yet
with higher bit depth). The reasons are shadow posterization on low bit
depth, and the fact that JPEG compression was designed for perceptually
uniform RGB and introduces shadow artifacts with linear RGB (see #1070,
message by Elle Stone). The only exception is when the creator was
working explicitly on 8-bit linear (not higher bit depth) AND if we
export the profile (otherwise most loaders around assume sRGB). In such
a case, let's consider the creator knows what one is doing and keep the
exported image linear.
Similar logics is already used in PNG exporter (though a bit of a
variant since PNG supports 16-bit so it is instead: 8-bit linear without
profile is promoted to 16-bit non-linear, and kept 8-bit linear with
profile).
(cherry picked from commit 5f4cf53519)
... produces jpeg in linear color space.
The problem was that we were anyway always exporting to non-linear while
attaching a linear profile. A first approach would have been to export
in linear instead when the work image is linear, as proposed by mitch in
a first version of the patch. Yet as Elle Stone notes, it is not a great
idea to export 8-bit images as linear.
Instead let's continue to always export as non-linear, as we were
already doing. Yet when we also save a profile, and this one was
originally linear, let's convert it to sRGB TRC before exporting.
(cherry picked from commit 8594275bb7)
Add flag GIMP_METADATA_SAVE_COLOR_PROFILE to GimpMetadataSaveFlags and
initialize it from gimp_export_color_profile() in
gimp_image_metadata_save_prepare().
Adapt all plug-ins to use the bit from the suggested export flags and
pass the actually used value back to
gimp_image_metadata_save_finish().
This changes no behavior at all but creates hooks on the libgimp side
that are called with the context of an image before and after the
actual export, which might become useful later. Also, consistency
is good even though the color profile is not strictly "metadata".
(cherry picked from commit c667fdc5c0)
...export dialogs
Move most stuff out of the "Advanced" expander, only nerdish encoding
options are left there.
Issue #701: Add a "Save color profile" toggle which honors the default
value configured in preferences and always saves the profile when
enabled.
(cherry picked from commit 540cfa9611)
I am going to forbid plug-ins from being installed directly in the root
of the plug-ins/ directory. They will have to be installed in a
subdirectory named the same as the entry point binary.
This may seem useless for our core plug-ins which are nearly all
self-contained in single binaries, but this is actually a necessary
restriction to eliminate totally the DLL hell issue on Windows. Moving
core plug-ins in subfolders is only a necessary consequence for it.
(cherry picked from commit 870ca6334d)
Various plug-ins exporting metadata should now follow preferences, which
would override any default. Of course these preferences can still be
overriden by saved settings (global parasite), previous run settings,
and finally through the GUI when interactive.
This is a privacy concern. Whereas importing metadata is usually a good
idea, exporting it should be a conscious action. A lot of private data
can be leaked through metadata and many people don't realize it (which
also usually means they don't need it). On the other hand, the people
who realize it are the ones who would explicitly edit the metadata and
check what they want to be exported or not.
This is only a first step. Some people may want to always export the
metadata and for these people, there should be abilities to change the
default.
Load as much of a broken/truncated JPEG as possible:
As soon as loading the scanlines has started, set a new setjmp()
location that doesn't abort loading alltogether but keeps the loaded
part of the image.
...in both the core and libgimp.
Images now know what the default mode for new layers is:
- NORMAL for empty images
- NORMAL for images with any non-legacy layer
- NORMAL_LEGAVY for images with only legacy layers
This changes behavior when layers are created from the UI, but *also*
when created by plug-ins (yes there is a compat issue here):
- Most (all?) single-layer file importers now create NORMAL layers
- Screenshot, Webpage etc also create NORMAL layers
Scripts that create images from scratch (logos etc) should not be
affected because they usually have NORMAL_LEGACY hardcoded.
3rd party plug-ins and scripts will also behave old-style unless they
get ported to gimp_image_get_default_new_layer_mode().
with proper value names. Mark most values as _BROKEN because they use
weird alpha compositing that has to die. Move GimpLayerModeEffects to
libgimpbase, deprecate it, and set it as compat enum for GimpLayerMode.
Add the GimpLayerModeEffects values as compat constants to script-fu
and pygimp.
Set use_orig_quality when both the quality and the subsampling are the
same as in the originally-imported jpeg.
Also improve subsampling initial selection: use the original subsampling
unless the default one is the best or the original one is the worst.
The current code was wrong and would often use the default subsampling
even when worse than the original one.
Rather than just discovering them by chance, a simple grep and some
search and replace are much more efficient! :-)
Cleaning only done on C and automake files.
it used to be a typedef to gpointer and actually was a cmsHPROFILE.
Change its API to be more "standard", remove the public close()
function. The object caches both the cmsHPROFILE and the data/length
ICC blob, so conversions between the two become obsolete (simply call
get_lcms_profile() or get_icc_profile()).
Adapt everything to the new API, but port it in a naive way for now,
the code doesn't take advantage of the new possibilities yet (like
refcounting).
gimp_color_config_get_foo_profile() -> get_foo_color_profile()
because the old names clash with possible future accessors for the raw
filename properties.
Return flags based on what metadata is actually present in the image.
Returning of a suggested value for GIMP_METADATA_SAVE_THUMBNAIL needs
support from gimp_image_metadata_load_prepare() and is still missing.
Port all plug-ins to use the new API, the suggested values are however
overridden by parasites and whatever special code was devised for the
individual plug-ins. This needs to be fixed.
Arithmetic coding is a feature of the JPEG standard. Although libjpeg
had always implemented arithmetic coding, it was compiled out by default
due to patents.
Those patents have now expired.
libjpeg 8 now enables arithmetic coding by default. Distributions which
use libjpeg < 8 can also support arithmetic coding by using the
appropriate CFLAGS to enable it. libjpeg-turbo 1.3.1 also has support
for arithmetic coding and is in popular shipping distributions.
Software such as jpegtran can losslessly convert Huffman compressed
images to arithmetic coding and vice versa. The lossy behavior of JPEG
does not happen at this (bit coding) layer of the format.
This initial patch provides a checkbox (disabled by default) to create
files which use arithmetic coding. It also has a tooltip warning that
such files may not be compatible with older decoders.
