Babl-0.1.52
Contents
• Babl
• Features
• Download
• Documentation
• Usage
• Vocabulary
• Environment
• Extending
• Directory Overview
• Todo
• Copyright
• Authors
babl is a dynamic, any to any, pixel format translation library.
It allows converting between different methods of storing pixels known
as pixel formats that have with different bitdepths and other data
representations, color models, color spaces and component permutations.
A vocabulary to formulate new pixel formats from existing primitives is
provided as well as the framework to add new color models, spaces and
data types.
Features
• ANSI C without external dependencies, works on win32, linux and
mac, 32bit and 64bit systems.
• Stable, small API, with singleton objects returned.
• Extendable with new formats, color models, components and
datatypes.
• Can load color spaces from ICC v2 and v4 profiles containing RGB
matrix + TRC.
• Reference 64bit floating point conversions for datatypes and color
models.
• Self profiling and optimizing, optimizing accuracy and performance
at runtime when the best performing single or multi-step conversion
path is chosen.
GEGL through GeglBuffer provides tiled buffers with on disk storage as
well as linear buffers with accessor functions for efficient data
access transparently using babl fishes for translation to the desired
pixel formats.
Download
The latest versioned development version of babl can be found in https:
//download.gimp.org/pub/babl/.
Babl uses git. The main repository is hosted by GNOME. It can be
browsed online and cloned with:
git clone git://git.gnome.org/babl
NEWS
The following is a list of the major changes that have gone into each
babl release. If there are significant improvements to babl when a GEGL
release is done a babl release is most often put out just prior to the
GEGL release.
2018-06-02 babl-0.1.52
Concurrency fixes and fixes to handling of 0/1 entry palettes, do
not pre-equalize XYZ conversion matrices for sRGB, internal
clean-ups, pre-define ACES2065-1 and ACEScg BablSpaces, add R~G~B~
set of spaces, which for all BablSpaces mean use sRGB TRC.
2018-05-20 babl-0.1.50
Improvements to speed and precision of indexed code, improvements
to meson build.
2018-05-15 babl-0.1.48
fix u8 <-> double conversions for chroma, SSE2 version of RGBA
float to CIE L / Lab. Build with -Ofast by default.
2018-04-10 babl-0.1.46
added extensions with more coverage for u32, half and other utilit
fast paths improving fast path coverage.
2018-02-18 babl-0.1.44
Fix bug in custom primaries/ICC fast paths, improve meson build
2018-01-23 babl-0.1.42
Fully initialize fishes when loading from cache.
2018-01-16 babl-0.1.40
Added format "CIE XYZ alpha" color model and formats. New API
babl_process_rows for reduced overhead in some scenarios; though
bigger gains seen also for regular babl_process with reimplemented
branch-free dispatch, and faster cbrt. Added meson build; being
tested in parallel with auotmake, Improved reference conversions
for formats skipping some of models components, Fixed gamma
handling in indexed/palettized formats and improved gamma precision
consistenct in sse2 conversions.
2017-11-15 babl-0.1.38
Added format "CIE L float", a couple of protections against
division by 0.0
2017-11-10 babl-0.1.36
Optimized customized primary aware code paths for CIE Lab<->RGB
conversions, improved accuracy of gamma approximations. New API
babl_format_exists() for checking validity of babl format name,
crash proofing of cache handling and use of environment variables.
2017-10-06 babl-0.1.34
Brown paper bag release, Fix indexed / custom primaries conflict,
and re-export a symbol used by old GEGL/GIMPs.
2017-10-03 babl-0.1.32
Added custom primaries and TRC support through ICC parsing,
improved float<->half performance, rewrite of all conversions
functions to adhere to new signature.
2017-07-15 babl-0.1.30
Thread stability for palette modes, stricter alpha preservation,
now cross-compilable on android.
2017-05-30 babl-0.1.28
Fast paths for Lav <-> Lch, release triggered by pending GIMP
release.
2017-05-09 babl-0.1.26
Build and install HCY color space, platform independences fixes to
fish cache.
2017-02-01 babl-0.1.24
Improvements to profile cache persistance, fast paths that improve
actual GIMP use on various precisions, use single precision
constants for some more of CIE computions.
2016-11-05 babl-0.1.22
Added cache of profiled conversions, added HCY color model, some
precision and performance updated for fast paths.
2016-11-05 babl-0.1.20
Fix run-time errors, leaks, and race conditions. Add conditional
fast paths.
2016-06-13 babl-0.1.18
Bugfix: take alpha threshold in consideration when processing
floats in SSE2.
2016-02-12 babl-0.1.16
Improvements to half float reference, SIMD, and fast-paths, and CIE
float fast paths; cleanups of fast path extensions.
2015-11-19 babl-0.1.14
sRGB precision tuning, stability fixes, locale fix for setting
error tolerance.
2015-02-03 babl-0.1.12
optimizations for floating point conversions, HSV and HSL color
models, removal of dead code, fixed CIE Lab conversions.
2012-03-30 babl-0.1.10
LUT based speedups for gamma correction / uncorrection.
2012-03-30 babl-0.1.8
Added support for indexed/pallette based formats, constified API.
2011-11-18 babl-0.1.6
Build improvements, remove blatantly wrong conversions from
extensions, made it possible to distinguish format_n formats from
others, improvements to vala/gobject introspection support.
2011-01-20 babl-0.1.4
Improved cross platform build ability, added code to handle
n-component formats, remove extraenous runtime profiling that
impacted performance.
2010-01-15 babl-0.1.2
Made babl mostly threadsafe (sufficient for GIMP/GEGLs needs).
Streamlined core functionality, reducing number of function calls
and removing overeager instrumentation.
2009-05-20 babl-0.1.0
Support for RGBA representation in the frequency domain,
un-pre-multiply close-to-zero alpha values to complete black
instead of slightly brighter than black, add a BABL_ALPHA_THRESHOLD
constant to the API, do a complete overhaul of the babl API and do
some changes to increase portability of the library.
2008-06-12 babl-0.0.22
Speed improvements due to: coalesced hashing, early bail out upon
creation of duplicate formats, caching of non existing paths. Large
amounts of the core has also been reviewed and refactored. Improved
conversion coverage in the matrix.
2008-02-27 babl-0.0.20
Builds on OSX Check <0.0 and >1.0 values conversions for accuracy
as well.
For more news see git log.
Documentation
When using BablFishes to do your conversions, you request a fish to
convert between two formats, and an optimal fish to babls capability is
provided that you can use to do your conversions. Babl also provides
the capability to describe new formats based on a vocabulary of user
registered color models and data types.
Babl provides a base vocabulary in BablBase and some extensions that
are thought to be generally useful.
When performing further extensions to the vocabulary of babl, the
internal consistency is governed by reference conversions that operate
on double (64 bit floating point values). The only color model created
during BablCore bootstrap is RGBA (linear light RGB, 0.0 - 1.0, with a
linear 0.0 - 1.0 opacity channel) backed by the double datatype.
Defined similarily to scRGB using 64bit floating point.
If babls conversion isn't fast enough, you can provide your own
conversion shortcut between two formats. The registered shortcut might
also be used by babl as an intermediate conversion when constructing
BablFishes for other conversions.
Babl extensions are shared objects. If you have already developed some
fast conversion functions, wrapping them as babl extensions should not
take much time and will speed up babl for other users as well.
Usage
babl_process (babl_fish (source_format, destination_format),
source_buffer, destination_buffer,
pixel_count);
The processing operation that babl performs is copying including
conversions if needed between linear buffers containing the same count
of pixels, with different pixel formats.
int width = 123, height = 581, pixel_count = width * height;
const Babl *srgb = babl_format ("R'G'B' u8");
const Babl *lab = babl_format ("CIE Lab float");
const Babl *srgb_to_lab_fish = babl_fish (srgb, lab);
float *lab_buffer;
unsigned char *srgb_buffer;
babl_init ();
srgb_buffer = malloc (pixel_count * babl_format_get_bytes_per_pixel (srgb));
lab_buffer = malloc (pixel_count * 3 * sizeof (float));
...... load data into srgb_buffer .......
babl_process (srgb_to_lab_fish, srgb_buffer, lab_buffer, pixel_count);
...... do operation in lab space ........
babl_process (babl_fish(lab, srgb),
lab_buffer, srgb_buffer, pixel_count);
/* the data has now been transformed back to srgb data */
If the existing pixel formats are not sufficient for your conversion
needs, new ones can be created on the fly. The constructor will provide
the prior created one if duplicates are registered.
const Babl *format = babl_format_new (babl_model ("R'G'B'"),
babl_type ("u16"),
babl_component ("B'"),
babl_component ("G'"),
babl_component ("R'"),
NULL);
Color Management
By default the babl API is assuming data to be (unbounded) sRGB data,
data being sRGB defines the conversion to and from gray-scale as well
as the gamma - or Transfer Response Curve, TRC, used for converting
between linear and non-linear variants of the data.
There is also a babl API call for creating a format for a specific
space. babl_format_with_space("R'G'B' u16", babl_space ("Rec2020"))
creates a 16 bit integer format for the Rec2020 color space. Babl knows
internally about "sRGB", "Rec2020", "Adobe", "Apple" and "ProPhoto"
spaces, as they are defined with constants on their wikipedia pages.
Additional spaces can be loaded from monitor-class matrix+TRC ICC v2
and v4 profiles. Using babl_icc_make_space (see babl.h for details).
The space of a babl format can also be queried with
babl_format_get_space.
The conversions babl does with ICC profiles are according to what is
known as the relative-colorimetric intent, monitor profiles containing
both the matrices used by babl and 3d CLUTs (color look up tables) most
often also do relative-colorimetric transfer for the "perceptual"
intent CLUTs, but with a more flexible and possibly higher accuracy
conversions. If babl adds support for loading and using CLUTs it will
be thus the perceptual intent will by babl be considered a different
albeit more accurate relative-colorimetric RGB space.
Vocabulary
+-
Data types
double
bits
64
bytes
8
u15
bits
16
bytes
2
half
bits
16
bytes
2
float
bits
32
bytes
4
u8
bits
8
bytes
1
u8-luma
bits
8
bytes
1
u8-chroma
bits
8
bytes
1
u16
bits
16
bytes
2
u32
bits
32
bytes
4
CIE u8 L
bits
8
bytes
1
CIE u8 ab
bits
8
bytes
1
CIE u16 L
bits
16
bytes
2
CIE u16 ab
bits
16
bytes
2
Color models
RGBA
components
R
G
B
A
RGB
components
R
G
B
RaGaBaA
components
Ra
Ga
Ba
A
R'G'B'
components
R'
G'
B'
R~G~B~
components
R~
G~
B~
R'G'B'A
components
R'
G'
B'
A
R~G~B~A
components
R~
G~
B~
A
R'aG'aB'aA
components
R'a
G'a
B'a
A
R~aG~aB~aA
components
R~a
G~a
B~a
A
Y
components
Y
YA
components
Y
A
YaA
components
Ya
A
Y'
components
Y'
Y'A
components
Y'
A
Y'aA
components
Y'a
A
Y~
components
Y~
Y~A
components
Y~
A
Y'CbCr
components
Y'
Cb
Cr
Y'CbCrA
components
Y'
Cb
Cr
A
CIE Lab
components
CIE L
CIE a
CIE b
CIE Lab alpha
components
CIE L
CIE a
CIE b
A
CIE LCH(ab)
components
CIE L
CIE C(ab)
CIE H(ab)
CIE LCH(ab) alpha
components
CIE L
CIE C(ab)
CIE H(ab)
A
CIE XYZ
components
CIE X
CIE Y
CIE Z
CIE XYZ alpha
components
CIE X
CIE Y
CIE Z
A
HCYA
components
hue
HCY chroma
HCY luma
alpha
HCY
components
hue
HCY chroma
HCY luma
HSLA
components
hue
saturation
lightness
alpha
HSL
components
hue
saturation
lightness
Y'CbCr709
components
Y'
Cb
Cr
Y'CbCrA709
components
Y'
Cb
Cr
alpha
HSVA
components
hue
saturation
value
alpha
HSV
components
hue
saturation
value
CMYK
components
cyan
magenta
yellow
key
CMY
components
cyan
magenta
yellow
Pixel formats
RGBA double
bytes/pixel
32
model
RGBA
components
double R
double G
double B
double A
RGB double
bytes/pixel
24
model
RGB
components
double R
double G
double B
RaGaBaA double
bytes/pixel
32
model
RaGaBaA
components
double Ra
double Ga
double Ba
double A
R'G'B' double
bytes/pixel
24
model
R'G'B'
components
double R'
double G'
double B'
R~G~B~ double
bytes/pixel
24
model
R~G~B~
components
double R~
double G~
double B~
R'G'B'A double
bytes/pixel
32
model
R'G'B'A
components
double R'
double G'
double B'
double A
R~G~B~A double
bytes/pixel
32
model
R~G~B~A
components
double R~
double G~
double B~
double A
R'aG'aB'aA double
bytes/pixel
32
model
R'aG'aB'aA
components
double R'a
double G'a
double B'a
double A
R~aG~aB~aA double
bytes/pixel
32
model
R~aG~aB~aA
components
double R~a
double G~a
double B~a
double A
R~G~B~ u8
bytes/pixel
3
model
R~G~B~
components
u8 R~
u8 G~
u8 B~
R'G'B' u8
bytes/pixel
3
model
R'G'B'
components
u8 R'
u8 G'
u8 B'
R'G'B'A u8
bytes/pixel
4
model
R'G'B'A
components
u8 R'
u8 G'
u8 B'
u8 A
R~G~B~A u8
bytes/pixel
4
model
R~G~B~A
components
u8 R~
u8 G~
u8 B~
u8 A
RGBA float
bytes/pixel
16
model
RGBA
components
float R
float G
float B
float A
RGB float
bytes/pixel
12
model
RGB
components
float R
float G
float B
RGB half
bytes/pixel
6
model
RGB
components
half R
half G
half B
RGBA half
bytes/pixel
8
model
RGBA
components
half R
half G
half B
half A
RaGaBaA half
bytes/pixel
8
model
RaGaBaA
components
half Ra
half Ga
half Ba
half A
R'G'B' half
bytes/pixel
6
model
R'G'B'
components
half R'
half G'
half B'
R'G'B'A half
bytes/pixel
8
model
R'G'B'A
components
half R'
half G'
half B'
half A
R'aG'aB'aA half
bytes/pixel
8
model
R'aG'aB'aA
components
half R'a
half G'a
half B'a
half A
R~G~B~ half
bytes/pixel
6
model
R~G~B~
components
half R~
half G~
half B~
R~G~B~A half
bytes/pixel
8
model
R~G~B~A
components
half R~
half G~
half B~
half A
R~aG~aB~aA half
bytes/pixel
8
model
R~aG~aB~aA
components
half R~a
half G~a
half B~a
half A
RGB u15
bytes/pixel
6
model
RGB
components
u15 R
u15 G
u15 B
RGBA u15
bytes/pixel
8
model
RGBA
components
u15 R
u15 G
u15 B
u15 A
RaGaBaA u15
bytes/pixel
8
model
RaGaBaA
components
u15 Ra
u15 Ga
u15 Ba
u15 A
R'G'B' u15
bytes/pixel
6
model
R'G'B'
components
u15 R'
u15 G'
u15 B'
R'G'B'A u15
bytes/pixel
8
model
R'G'B'A
components
u15 R'
u15 G'
u15 B'
u15 A
R'aG'aB'aA u15
bytes/pixel
8
model
R'aG'aB'aA
components
u15 R'a
u15 G'a
u15 B'a
u15 A
RGB u32
bytes/pixel
12
model
RGB
components
u32 R
u32 G
u32 B
RGBA u32
bytes/pixel
16
model
RGBA
components
u32 R
u32 G
u32 B
u32 A
RaGaBaA u32
bytes/pixel
16
model
RaGaBaA
components
u32 Ra
u32 Ga
u32 Ba
u32 A
R'G'B' u32
bytes/pixel
12
model
R'G'B'
components
u32 R'
u32 G'
u32 B'
R'G'B'A u32
bytes/pixel
16
model
R'G'B'A
components
u32 R'
u32 G'
u32 B'
u32 A
R'aG'aB'aA u32
bytes/pixel
16
model
R'aG'aB'aA
components
u32 R'a
u32 G'a
u32 B'a
u32 A
R~G~B~ u32
bytes/pixel
12
model
R~G~B~
components
u32 R~
u32 G~
u32 B~
R~G~B~A u32
bytes/pixel
16
model
R~G~B~A
components
u32 R~
u32 G~
u32 B~
u32 A
R~aG~aB~aA u32
bytes/pixel
16
model
R~aG~aB~aA
components
u32 R~a
u32 G~a
u32 B~a
u32 A
Y double
bytes/pixel
8
model
Y
components
double Y
YA double
bytes/pixel
16
model
YA
components
double Y
double A
YaA double
bytes/pixel
16
model
YaA
components
double Ya
double A
Y' double
bytes/pixel
8
model
Y'
components
double Y'
Y'A double
bytes/pixel
16
model
Y'A
components
double Y'
double A
Y'aA double
bytes/pixel
16
model
Y'aA
components
double Y'a
double A
Y~ double
bytes/pixel
8
model
Y~
components
double Y~
Y~A double
bytes/pixel
16
model
Y~A
components
double Y~
double A
YA half
bytes/pixel
4
model
YA
components
half Y
half A
YaA half
bytes/pixel
4
model
YaA
components
half Ya
half A
Y half
bytes/pixel
2
model
Y
components
half Y
Y'A half
bytes/pixel
4
model
Y'A
components
half Y'
half A
Y'aA half
bytes/pixel
4
model
Y'aA
components
half Y'a
half A
Y' half
bytes/pixel
2
model
Y'
components
half Y'
YA u15
bytes/pixel
4
model
YA
components
u15 Y
u15 A
YaA u15
bytes/pixel
4
model
YaA
components
u15 Ya
u15 A
Y u15
bytes/pixel
2
model
Y
components
u15 Y
Y'A u15
bytes/pixel
4
model
Y'A
components
u15 Y'
u15 A
Y'aA u15
bytes/pixel
4
model
Y'aA
components
u15 Y'a
u15 A
Y' u15
bytes/pixel
2
model
Y'
components
u15 Y'
YA u32
bytes/pixel
8
model
YA
components
u32 Y
u32 A
YaA u32
bytes/pixel
8
model
YaA
components
u32 Ya
u32 A
Y u32
bytes/pixel
4
model
Y
components
u32 Y
Y'A u32
bytes/pixel
8
model
Y'A
components
u32 Y'
u32 A
Y'aA u32
bytes/pixel
8
model
Y'aA
components
u32 Y'a
u32 A
Y' u32
bytes/pixel
4
model
Y'
components
u32 Y'
Y'CbCr double
bytes/pixel
24
model
Y'CbCr
components
double Y'
double Cb
double Cr
Y'CbCrA double
bytes/pixel
32
model
Y'CbCrA
components
double Y'
double Cb
double Cr
double A
Y'CbCr u8
bytes/pixel
3
model
Y'CbCr
components
u8-luma Y'
u8-chroma Cb
u8-chroma Cr
R'aG'aB'aA float
bytes/pixel
16
model
R'aG'aB'aA
components
float R'a
float G'a
float B'a
float A
R~aG~aB~aA float
bytes/pixel
16
model
R~aG~aB~aA
components
float R~a
float G~a
float B~a
float A
R'G'B'A float
bytes/pixel
16
model
R'G'B'A
components
float R'
float G'
float B'
float A
R~G~B~A float
bytes/pixel
16
model
R~G~B~A
components
float R~
float G~
float B~
float A
R'G'B' float
bytes/pixel
12
model
R'G'B'
components
float R'
float G'
float B'
R~G~B~ float
bytes/pixel
12
model
R~G~B~
components
float R~
float G~
float B~
Y' float
bytes/pixel
4
model
Y'
components
float Y'
Y~ float
bytes/pixel
4
model
Y~
components
float Y~
Y'A float
bytes/pixel
8
model
Y'A
components
float Y'
float A
Y~A float
bytes/pixel
8
model
Y~A
components
float Y~
float A
Y'aA float
bytes/pixel
8
model
Y'aA
components
float Y'a
float A
RaGaBaA float
bytes/pixel
16
model
RaGaBaA
components
float Ra
float Ga
float Ba
float A
YA float
bytes/pixel
8
model
YA
components
float Y
float A
YaA float
bytes/pixel
8
model
YaA
components
float Ya
float A
Y float
bytes/pixel
4
model
Y
components
float Y
Y~ half
bytes/pixel
2
model
Y~
components
half Y~
Y~A half
bytes/pixel
4
model
Y~A
components
half Y~
half A
R'aG'aB'aA u8
bytes/pixel
4
model
R'aG'aB'aA
components
u8 R'a
u8 G'a
u8 B'a
u8 A
R~aG~aB~aA u8
bytes/pixel
4
model
R~aG~aB~aA
components
u8 R~a
u8 G~a
u8 B~a
u8 A
Y' u8
bytes/pixel
1
model
Y'
components
u8 Y'
Y~ u8
bytes/pixel
1
model
Y~
components
u8 Y~
Y'A u8
bytes/pixel
2
model
Y'A
components
u8 Y'
u8 A
Y~A u8
bytes/pixel
2
model
Y~A
components
u8 Y~
u8 A
Y'aA u8
bytes/pixel
2
model
Y'aA
components
u8 Y'a
u8 A
RGBA u8
bytes/pixel
4
model
RGBA
components
u8 R
u8 G
u8 B
u8 A
RGB u8
bytes/pixel
3
model
RGB
components
u8 R
u8 G
u8 B
RaGaBaA u8
bytes/pixel
4
model
RaGaBaA
components
u8 Ra
u8 Ga
u8 Ba
u8 A
YA u8
bytes/pixel
2
model
YA
components
u8 Y
u8 A
YaA u8
bytes/pixel
2
model
YaA
components
u8 Ya
u8 A
Y u8
bytes/pixel
1
model
Y
components
u8 Y
R'aG'aB'aA u16
bytes/pixel
8
model
R'aG'aB'aA
components
u16 R'a
u16 G'a
u16 B'a
u16 A
R~aG~aB~aA u16
bytes/pixel
8
model
R~aG~aB~aA
components
u16 R~a
u16 G~a
u16 B~a
u16 A
R'G'B'A u16
bytes/pixel
8
model
R'G'B'A
components
u16 R'
u16 G'
u16 B'
u16 A
R~G~B~A u16
bytes/pixel
8
model
R~G~B~A
components
u16 R~
u16 G~
u16 B~
u16 A
R'G'B' u16
bytes/pixel
6
model
R'G'B'
components
u16 R'
u16 G'
u16 B'
R~G~B~ u16
bytes/pixel
6
model
R~G~B~
components
u16 R~
u16 G~
u16 B~
Y' u16
bytes/pixel
2
model
Y'
components
u16 Y'
Y~ u16
bytes/pixel
2
model
Y~
components
u16 Y~
Y'A u16
bytes/pixel
4
model
Y'A
components
u16 Y'
u16 A
Y~A u16
bytes/pixel
4
model
Y~A
components
u16 Y~
u16 A
Y'aA u16
bytes/pixel
4
model
Y'aA
components
u16 Y'a
u16 A
RGBA u16
bytes/pixel
8
model
RGBA
components
u16 R
u16 G
u16 B
u16 A
RGB u16
bytes/pixel
6
model
RGB
components
u16 R
u16 G
u16 B
RaGaBaA u16
bytes/pixel
8
model
RaGaBaA
components
u16 Ra
u16 Ga
u16 Ba
u16 A
YA u16
bytes/pixel
4
model
YA
components
u16 Y
u16 A
YaA u16
bytes/pixel
4
model
YaA
components
u16 Ya
u16 A
Y u16
bytes/pixel
2
model
Y
components
u16 Y
Y~ u32
bytes/pixel
4
model
Y~
components
u32 Y~
Y~A u32
bytes/pixel
8
model
Y~A
components
u32 Y~
u32 A
Y'CbCr float
bytes/pixel
12
model
Y'CbCr
components
float Y'
float Cb
float Cr
Y'CbCrA float
bytes/pixel
16
model
Y'CbCrA
components
float Y'
float Cb
float Cr
float A
cairo-RGB24
bytes/pixel
4
model
R'G'B'
components
u8 B'
u8 G'
u8 R'
u8 PAD
CIE Lab double
bytes/pixel
24
model
CIE Lab
components
double CIE L
double CIE a
double CIE b
CIE Lab alpha double
bytes/pixel
32
model
CIE Lab alpha
components
double CIE L
double CIE a
double CIE b
double A
CIE LCH(ab) double
bytes/pixel
24
model
CIE LCH(ab)
components
double CIE L
double CIE C(ab)
double CIE H(ab)
CIE LCH(ab) alpha double
bytes/pixel
32
model
CIE LCH(ab) alpha
components
double CIE L
double CIE C(ab)
double CIE H(ab)
double A
CIE XYZ double
bytes/pixel
24
model
CIE XYZ
components
double CIE X
double CIE Y
double CIE Z
CIE XYZ alpha double
bytes/pixel
32
model
CIE XYZ alpha
components
double CIE X
double CIE Y
double CIE Z
double A
CIE Lab float
bytes/pixel
12
model
CIE Lab
components
float CIE L
float CIE a
float CIE b
CIE XYZ float
bytes/pixel
12
model
CIE XYZ
components
float CIE X
float CIE Y
float CIE Z
CIE XYZ alpha float
bytes/pixel
16
model
CIE XYZ
components
float CIE X
float CIE Y
float CIE Z
float A
CIE Lab alpha float
bytes/pixel
16
model
CIE Lab alpha
components
float CIE L
float CIE a
float CIE b
float A
CIE L float
bytes/pixel
4
model
CIE Lab
components
float CIE L
CIE L alpha float
bytes/pixel
8
model
CIE Lab alpha
components
float CIE L
float A
CIE Lab u8
bytes/pixel
3
model
CIE Lab
components
CIE u8 L CIE L
CIE u8 ab CIE a
CIE u8 ab CIE b
CIE Lab u16
bytes/pixel
6
model
CIE Lab
components
CIE u16 L CIE L
CIE u16 ab CIE a
CIE u16 ab CIE b
CIE LCH(ab) float
bytes/pixel
12
model
CIE LCH(ab)
components
float CIE L
float CIE C(ab)
float CIE H(ab)
CIE LCH(ab) alpha float
bytes/pixel
16
model
CIE LCH(ab) alpha
components
float CIE L
float CIE C(ab)
float CIE H(ab)
float A
HCYA double
bytes/pixel
32
model
HCYA
components
double hue
double HCY chroma
double HCY luma
double alpha
HCY double
bytes/pixel
24
model
HCY
components
double hue
double HCY chroma
double HCY luma
HCYA float
bytes/pixel
16
model
HCYA
components
float hue
float HCY chroma
float HCY luma
float alpha
HCY float
bytes/pixel
12
model
HCY
components
float hue
float HCY chroma
float HCY luma
B'aG'aR'aA u8
bytes/pixel
4
model
R'aG'aB'aA
components
u8 B'a
u8 G'a
u8 R'a
u8 A
HSLA double
bytes/pixel
32
model
HSLA
components
double hue
double saturation
double lightness
double alpha
HSL double
bytes/pixel
24
model
HSL
components
double hue
double saturation
double lightness
HSLA float
bytes/pixel
16
model
HSLA
components
float hue
float saturation
float lightness
float alpha
HSL float
bytes/pixel
12
model
HSL
components
float hue
float saturation
float lightness
cairo-ARGB32
bytes/pixel
4
model
R'aG'aB'aA
components
u8 B'a
u8 G'a
u8 R'a
u8 A
cairo-A8
bytes/pixel
1
model
YA
components
u8 A
Y'CbCr709 double
bytes/pixel
24
model
Y'CbCr709
components
double Y'
double Cb
double Cr
Y'CbCrA709 double
bytes/pixel
32
model
Y'CbCrA709
components
double Y'
double Cb
double Cr
double alpha
Y'CbCrA709 float
bytes/pixel
16
model
Y'CbCrA709
components
float Y'
float Cb
float Cr
float alpha
Y'CbCr709 float
bytes/pixel
12
model
Y'CbCr709
components
float Y'
float Cb
float Cr
HSVA double
bytes/pixel
32
model
HSVA
components
double hue
double saturation
double value
double alpha
HSV double
bytes/pixel
24
model
HSV
components
double hue
double saturation
double value
HSVA float
bytes/pixel
16
model
HSVA
components
float hue
float saturation
float value
float alpha
HSV float
bytes/pixel
12
model
HSV
components
float hue
float saturation
float value
CMYK double
bytes/pixel
32
model
CMYK
components
double cyan
double magenta
double yellow
double key
CMY double
bytes/pixel
24
model
CMY
components
double cyan
double magenta
double yellow
CMYK float
bytes/pixel
16
model
CMYK
components
float cyan
float magenta
float yellow
float key
CMY float
bytes/pixel
12
model
CMY
components
float cyan
float magenta
float yellow
CMYK u8
bytes/pixel
4
model
CMYK
components
u8 cyan
u8 magenta
u8 yellow
u8 key
Environment
Through the environment variable BABL_TOLERANCE you can control a speed
/performance trade off that by default is set very low (0.000001)
values in the range 0.01-0.1 can provide reasonable preview performance
by allowing lower numerical accuracy
.
BABL_PATH contains the path of the directory, containing the .so
extensions to babl.
Extending
For samples of how the current internal API specification of data
types, color models, and conversions look in the extensions/ directory.
The tables in this HTML file is directly generated based on the data
registered by BablCore (double and RGBA), BablBase (core datatypes, and
RGB models), extensions (CIE Lab, naive CMYK, various shortcut
conversions).
Directory Overview
babl-dist-root
│
├──babl the babl core
│ └──base reference implementations for RGB and Grayscale Color Models,
│ 8bit 16bit, and 32bit and 64bit floating point.
├──extensions CIE-Lab color model as well as a naive-CMYK color model.
│ also contains a random cribbage of old conversion optimized
│ code from gggl. Finding more exsisting conversions in third
│ part libraries (hermes, lcms?, liboil?) could improve the
│ speed of babl.
├──tests tests used to keep babl sane during development.
└──docs Documentation/webpage for babl (the document you are reading
originated there.
TODO
• Support for conversions between formats that have higher
dimensionality than RGBA.
• Support for datatypes that are not a multiple of 8bit.
Copyright
Babl is free software; you can redistribute it and/or modify it under
the terms of the GNU Lesser General Public License as published by the
Free Software Foundation; either version 3 of the License, or (at your
option) any later version.
Authors
Øyvind Kolås pippin at gimp.org
Original author.
Sven Neumann sven at gimp.org
Build sanity and optimizations.
Michael Natterer mitch at gimp.org
Build sanity.
Kevin Cozens kcozens at cvs.gnome.org
Build sanity.
Tim Mooney
Portability fixes.
Michael Schumacher schumaml at cvs.gnome.org
win32 support for dynamic extensions.
Portability fixes.
Jan Heller jheller at svn.gnome.org
Optimizations, refactoring and documentation.
Mukund Sivaraman muks at mukund.org
Sparse fixes and sanity.
dmacks at netspace.org
Build sanity
Sam Hocevar
Build sanity.
Zhang Junbo
Frequency domain color model.
Martin Nordholts
Optimizations and API overhaul.
Gary V. Vaughan
Multiplatform build support.
Stanislav Brabec
Portability patch.
Hubert Figuiere
C++ friendliness patch.
Danny Robson
Code cleanups.
Fryderyk Dziarmagowski freetz at gmx.net
Code cleanups.
Daniel Paredes García danipga at gmail.com
Initial work to make babl threadsafe
Rupert Weber gimp at leguanease.org
Documentation and other improvements
Jehan jehan at girinstud.io
win32 portabilitiy
Sven Claussner
Update DOAP file
Alexander Larsson
Math optimizations
Nils Philippsen
code cleanups
Simon Budig
cleanups
Micheal Muré
portability fixes
Edward E
win32 platform adaptations
Maxime Nicco
HSV color model extension
Teo Mazars
Color spaces/models in extensions
Daniel Sabo
Dead code elimination, general cleanups,
Michael Henning
Conversion fixes
Elle Stone
Verification and improvements to accuracy of color space
conversions.
Thomas Manni
CIE related fixups
Roman Lebedev
Stability/crasher fixes
Jon Nordby
Portability, Stability and more
Massimo Valentini
stability fixes
Ell
fast paths
Félix Piédallu
Initial meson build
/babl-0.1.52