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Frequently asked questions
Basic questions
Q: What is little cms?
A:
- lcms is a library FOR PROGRAMMERS ONLY.
- lcms is FREE and does include SOURCE CODE.
- lcms deals with color management stuff.
- lcms is a CMM engine; it implements fast transforms
between ICC profiles.
- lcms is a standalone engine; it doesn't need ICM or ColorSync to work.
- lcms intends to be PORTABLE across several platforms.
- lcms is distributed under
the MIT license agreement .
Q: What is little cms NOT?
A:
- lcms is NOT a file format or display library. lcms knows
nothing about how to display bitmaps (JPEG, TIFF, GIF or whatever).
- lcms is NOT a complete color management solution.
- lcms is NOT commercial: thus, lcms is NOT supported software.
Q: How can I use lcms in my apps?
A:
lcms adds basic icc profile support. Then you can use the profiles
to prepare a bitmap for display, keeping the original image colors.
lcms is
also useful for quickly converting between color spaces. lcms can also
generate accurate separations based on the target printer, or inversely
it
can recover RGB data from a stored separation. Also, lcms can "Proof"
an image, showing the final colors as they would be rendered on a specific
device.
Less common usage would be to convert from RGB to CMYK accurately,
to convert separations done for one printer to another printer, to use
CIEL*a*b as working space, to read Lab TIFF, to characterize Colorimetric
PNG, etc. etc.
Q: Q: How much does little cms cost?
A:
Nothing. It is free under the MIT
license agreement. You can use lcms in your commercial apps, too.
This is an extremely liberal license. The
license requires a pointer referencing the lcms source code, so you can
add a file in your distribution disk saying that source code can be found
at this site. That's all. (Of course, if you use the package and can improve
on it, then your contribution will be welcome, but no contribution is
required.)
Q: Why the
MIT license ?
A:
lcms did use LGPL until revision 1.12, but after that,
we switched to the MIT license because is more suitable to commercial
products. If this is a
problem for you, drop me a note
and we can study alternatives
Q: I'm not a programmer. Can I benefit from little
cms?
A:
Even if you are not a programmer but you are interested
in colorimetry, you can still download the utility
programs to experiment with profiles and see how much images can change
when profiles are involved. Of course, programmers are also welcome! ;)
Portability questions.
Q: Which C/C++ compilers are supported?
A:
A lot! Borland, Microsoft, Metrowerks, gcc, and Watcom
have been tested, but it is likely others will also compile lcms.
Q: I see that lcms is written in "C". Can
I use it in my XXX programming language?
A:
If your XXX programming language supports pointers and
DLL calls, yes. lcms (as a DLL) uses the stdcall convention, so, it is
usable from Visual
Basic, for example. There is a special package for full Delphi support.
See the Delphi package for more details. On linux this applies to shared
libraries.
Q: Will lcms work with my XXX "C" compiler ?
A:
Probably YES. lcms is not using K&R, but the latest
ANSI standard, C99. Also, there are three different build modes for maximizing
compatibility: (1) ASM mode for fastest operation(on x86 processors),
(2) C-only fixed point for obtaining reasonable speed and big portability,
and (3) "float point" mode for processors with lightning-fast
floating point math.
.
Q: Does lcms work on Mac?
A:
Yes. It has been tested on G4, G5, Jaguar and Panther.
Q: Does lcms work on linux? My machine is a big-endian
one, will still work?
A:
Yes and Yes. Of course, if your C compiler accepts the code, as far as I know, there are also ports to FreeBSD, Solaris, Sun and even VMS. The best way to find out is to try it! ;)
Q: Does lcms work on Klynx?
A:
Yes, just use the shared library.
