lcms-user — For users of the little cms library

[Lcms-user] Need Advice

[Armindo Da S. <tec...@wa...>]

Hola Marti,


>lcms does support the four rendering intents. Also, a single profile can
>contain more than one intent.

>I would try perceptual & saturation, but I guess you will choose
>saturation as your working intent.

So I suppose that if the profile contains Saturation I must use LCMS with
Saturation also? What happened if I chose another value?



>Besides, I'm almost ready to release a new revision. This one does
>include scanner & monitor profilers. For printers, it will take a bit more
>time. A preview of new release can be found at www.littlecms.com/ver108.htm

I know how to drive a spectrocam (www.spectrostar.com), if I could help....

thanks

Armindo

Re: [Lcms-user] Need Advice

[<ma...@li...>]

Hi Armindo,

Pleased to meet you again :-)

lcms does support the four rendering intents. Also, a single profile can =

contain more than one intent.

The intent basically stands for the usage you would give to bitmap.
=20
The two more usefull intents are perceptual and saturation.

Perceptual is good for images, it tends to preserve contrast and makes
the image looking good. But it can move significantly given colors.

Saturation stands for logos, spot colors, etc. It tends to preserve the=20
amount of color. But it can make photos look ugly.

If I recall correctly, you are working on textile. On this particular =
stuff,=20
saturation will bring better color matching, as far as you give more=20
importance to the color that to the image.

There are two additional intents, relative colorimetric, used only as=20
a transport format, and absolute colorimetric, used on side-by-side=20
color match. Absolute colorimetric is useless on all but very specific=20
conditions, and relative colorimetric is only used on math calculations.

I would try perceptual & saturation, but I guess you will choose=20
saturation as your working intent.

Besides, I'm almost ready to release a new revision. This one does
include scanner & monitor profilers. For printers, it will take a bit =
more=20
time. A preview of new release can be found at =
www.littlecms.com/ver108.htm


Best Regards,
Marti.


  ----- Original Message -----=20
  From: Armindo Da Silva=20
  To: lcm...@li...=20
  Sent: Wednesday, October 31, 2001 10:18 AM
  Subject: [Lcms-user] Need Advice


  Hello,

  I have just bought Monaco Proof (windows Version) for creating =
profiles.

  the software ask me what type of rendering intent I want : Witch one =
to
  choose?

  and in LCMS should I use the same?

  I need to generate a profile for an epson with Monaco Proof , so if =
anybody
  have experience with this, and can give me some tips, it would be =
great!

  thanks

  Armindo

[Lcms-user] Need Advice

[Armindo Da S. <tec...@wa...>]

Hello,

I have just bought Monaco Proof (windows Version) for creating profiles.

the software ask me what type of rendering intent I want : Witch one to
choose?

and in LCMS should I use the same?

I need to generate a profile for an epson with Monaco Proof , so if =
anybody
have experience with this, and can give me some tips, it would be great!

thanks

Armindo

Re: [Lcms-user] error handling in lcms

[<ma...@li...>]

Hi,

> The only way I found to switch of the messag dialogs,was
> to set ERROR_IGNORE, but how can I implement my
> own error handling ???

Is fair easy, just create a global function called 

void cmsSignalError(int ErrorCode, const char *ErrorText, ...)

and another called

int cmsErrorAction(int nAction)

or don't call this latter (the engine doesn't it use in any place)

This will prevent from loading cmserr.c from library. Each error
will result in a call to your cmsSignalError, and here you can deal with 
it on your own.

This is explained on the tutorial, take a look on "error handling" section.

Hope this helps,
Marti.

----- Original Message ----- 
From: "Maik Wojcieszak" <mw...@wo...>
To: <lcm...@li...>
Sent: Wednesday, October 31, 2001 8:55 AM
Subject: [Lcms-user] error handling in lcms


> Hi,
> 
> How does lcms notify me about errors, if I don't want
> it to show me message on the desktop.
> 
> The only way I found to switch of the messag dialogs,was
> to set ERROR_IGNORE, but how can I implement my
> own error handling ???
> 
> Is there a way to use exceptions or read any error numbers ??
> 
> regards,
> maik
> 
> -------------------------------------------------
> Maik Wojcieszak
> 
> wobe-team (http://www.wobe-team.com)
> 
> 
> 
> _______________________________________________
> Lcms-user mailing list
> Lcm...@li...
> https://lists.sourceforge.net/lists/listinfo/lcms-user
> 
> 

[Lcms-user] error handling in lcms

[Maik W. <mw...@wo...>]

Hi,

How does lcms notify me about errors, if I don't want
it to show me message on the desktop.

The only way I found to switch of the messag dialogs,was
to set ERROR_IGNORE, but how can I implement my
own error handling ???

Is there a way to use exceptions or read any error numbers ??

regards,
maik

-------------------------------------------------
Maik Wojcieszak

wobe-team (http://www.wobe-team.com)

Re: [Lcms-user] Kodak patent infringement?

[<ma...@li...>]

Hi,

> I'm told that Kodak has some patents on color management.  Is lcms known
> to be free of them?

Not only Kodak... color management is fullfilled of patents.

Here are some:

http://www.frontiernet.net/~shyam/colormanagement.htm

Please note that these are USA patents, and does not apply worldwide.

I have tried to do my best to avoid any patent, and implement
only what the ICC spec provides. There was only one part, tetrahedral
interpolation, that was  under patent  when I wrote the core engine.
For this reason the default interpolation is trilinear and there is a toggle to
select tetrahedral at compile time. Anyway, Sakamoto's patent, is now expired.

I cannot assure the code is completly completly patent-free, but I have taken
this issue seriously. If you or anybody does know some portion of code
breaking any patent, please let me know. I will remove that part or provide
a workaround as fast as possible.

Regards,
Martí Maria
The little cms project
http://www.littlecms.com
ma...@li...


----- Original Message -----
From: "David Kaelbling" <dr...@sg...>
To: <lcm...@li...>
Sent: Tuesday, October 30, 2001 4:43 PM
Subject: [Lcms-user] Kodak patent infringement?


> Hi,
>
> I'm told that Kodak has some patents on color management.  Is lcms known
> to be free of them?
>
> David
>
> --
> David KAELBLING <dr...@sg...>     Silicon Graphics Computer Systems
> 1 Cabot Rd, suite 250; Hudson, MA 01749     781.839.2157, fax ...2357
>
> _______________________________________________
> Lcms-user mailing list
> Lcm...@li...
> https://lists.sourceforge.net/lists/listinfo/lcms-user
>
>

[Lcms-user] Kodak patent infringement?

[David K. <dr...@sg...>]

Hi,

I'm told that Kodak has some patents on color management.  Is lcms known
to be free of them?

	David

-- 
David KAELBLING <dr...@sg...>	    Silicon Graphics Computer Systems
1 Cabot Rd, suite 250; Hudson, MA 01749	    781.839.2157, fax ...2357

[Lcms-user] New snapshot of lcms-1.08 available on site

[<ma...@li...>]

Hi,

I have put a second beta snapshot of version 1.08 in

http://www.littlecms.com/ver108.htm

This adds some new features, like full Hexachrome (6 inks) support,
and a brand new monitor profiler as well.

I'm trying for now to make the scanner & monitor profilers and the
measurement tool run on KDE. Since all these programs are written
using trolltech's Qt, I guess this would be a straightforward process.
However, I'm not very familiar with KDE idiosincrasy. Anyone has a
bit of experience on it? Any clues will be very appreciated.

Best regards,
Martí Maria
The little cms project
http://www.littlecms.com
ma...@li...

[Lcms-user] Beta of scanner profiler available on site

[<ma...@li...>]

Hi,

I've put a early beta of the new scanner  profiler in the site:

http://www.littlecms.com/ver108.htm

Check it on "samples of profiler construction set". For now this is
a binary MS Windows only. You would also need the measurement
tool to build the measurement sheet from scanout and the Qt runtime
DLL in order to generate profiles.

Regards,
Martí Maria
The little cms project
http://www.littlecms.com
ma...@li...

[Lcms-user] New lcms revision

[<ma...@li...>]

Dear little cms mailing list subscribers:

As a gratitude to be on board, I've put a snapshop of the
new 1.08 revision on

http://www.littlecms.com/ver108.htm

We are not going to announce publicly this release until
whithin a month. Nevertheless, the cmm seems works fine and
there are many additions & enhancements.

While this is NOT the final 1.08 version, since it misses
some documentation and samples, we hope you would find
it interesting.

Sincerely,
Martí Maria
The little cms project
http://www.littlecms.com
ma...@li...

Re: [Lcms-user] Idiots guide to CMYK->RGB conversions

[<ma...@li...>]

Hi,=20

You almost got it... just replace TYPE_CMYK_16 with TYPE_CMYK_8, and =
SHORT with BYTE,=20
and your program will work.

The buffers are supposed to be arrays of values, since images are stored =
in such way,
the number at end of descriptor (e.g. TYPE_RGB_*) is the number of bits =
per component.=20
TYPE_RGB_8 is 8 bits, so r, g and b are regarded to be BYTEs. =
TYPE_RGB_16 is 16 bits,=20
then r, g, b are WORDs (this is for dealing with 16 bps images, not very =
common). There are=20
many descriptors, lcms can undestand a lot of layouts. As said, this =
works in such way=20
because scanlines of images are stored as arrays of values.

If you want to convert, say, 300 pixels at time, you will need 300 =
pixels x 3 components =3D=20
900 bytes, so you can use output buffer of 900 bytes;

   BYTE OutputBuffer[900];

In CMYK there are 4 components, so 300 x 4 =3D 1200 bytes

    BYTE InputBuffer[1200];

and for converting:

    cmsDoTransform(xform, InputBuffer, OutputBuffer, 300);


Another way to do this could be to use arrays of structs:

struct {
         BYTE r;
         BYTE g;
         BYTE b;

        } MyOutputBuffer[300];
    =20
That is 300, pixels of r, g, b
=20
struct {
         BYTE c;
        BYTE m;
        BYTE y;
        BYTE k;

        } MyInputBuffer[300];

That is, 300 pixels of cmyk

then you could use:=20

cmsDoTransform(xform, MyInputBuffer, MyOutputBuffer, 300)

Note that the number passed are pixels, not bytes.

Hope this helps,
Marti.


  ----- Original Message -----=20
  From: Brian Fallon=20
  To: lcm...@li...=20
  Sent: Saturday, April 28, 2001 6:57 PM
  Subject: [Lcms-user] Idiots guide to CMYK->RGB conversions


  Hi,

  I've looked at every message on this list and I can't figure out how =
to convert CMYK values into RGB values using the API

  I understand fully the concepts beign used here but I'm a total =
beginner when it comes to the C language.

  Please, please, could you send me some code on how to do this... If =
not please explain my question below.

  I've looked at the 'simple.c' file included with the source and I cant =
figure how to use it? What type are inputBuffer & outputBuffer. Do I =
pass an array of values into the function cmsDoTransform()?

  here is what I have being messing around with so far (see below), If =
anyone could make this work I would be able to adapt it into a simple =
program and that's all I need. Thanks a million....

  Brian Fallon


   SHORT inputBuffer[] =3D {0x00,0x00,0x00,0x00};
   SHORT outputBuffer[3];

      cmsHPROFILE hInProfile, hOutProfile;
      cmsHTRANSFORM hTransform;

      hInProfile  =3D =
cmsOpenProfileFromFile("D:/Downloads/Development/lcms/lcms107b/profiles/t=
r01_d50.icm", "r");
      hOutProfile =3D =
cmsOpenProfileFromFile("D:/Downloads/Development/lcms/Lcms107b/profiles/s=
RGB Color Space Profile.ICM", "r");=20
   hTransform =3D cmsCreateTransform(hInProfile, TYPE_CMYK_16, =
hOutProfile, TYPE_RGB_8, INTENT_PERCEPTUAL, 0);


   cmsDoTransform(hTransform, inputBuffer, outputBuffer, 1);


      cmsDeleteTransform(hTransform);
      cmsCloseProfile(hInProfile);
      cmsCloseProfile(hOutProfile);

   printf("Input values: cmyk( %d, %d, %d, %d )\n", inputBuffer[0], =
inputBuffer[1], inputBuffer[2], inputBuffer[3]);
   printf("Input values: rgb( %d, %d, %d)\n", outputBuffer[0], =
outputBuffer[1], outputBuffer[2]);
   return 0;=20
  }

[Lcms-user] Idiots guide to CMYK->RGB conversions

[Brian F. <br...@da...>]

Hi,

I've looked at every message on this list and I can't figure out how to =
convert CMYK values into RGB values using the API

I understand fully the concepts beign used here but I'm a total beginner =
when it comes to the C language.

Please, please, could you send me some code on how to do this... If not =
please explain my question below.

I've looked at the 'simple.c' file included with the source and I cant =
figure how to use it? What type are inputBuffer & outputBuffer. Do I =
pass an array of values into the function cmsDoTransform()?

here is what I have being messing around with so far (see below), If =
anyone could make this work I would be able to adapt it into a simple =
program and that's all I need. Thanks a million....

Brian Fallon


 SHORT inputBuffer[] =3D {0x00,0x00,0x00,0x00};
 SHORT outputBuffer[3];

    cmsHPROFILE hInProfile, hOutProfile;
    cmsHTRANSFORM hTransform;

    hInProfile  =3D =
cmsOpenProfileFromFile("D:/Downloads/Development/lcms/lcms107b/profiles/t=
r01_d50.icm", "r");
    hOutProfile =3D =
cmsOpenProfileFromFile("D:/Downloads/Development/lcms/Lcms107b/profiles/s=
RGB Color Space Profile.ICM", "r");=20
 hTransform =3D cmsCreateTransform(hInProfile, TYPE_CMYK_16, =
hOutProfile, TYPE_RGB_8, INTENT_PERCEPTUAL, 0);


 cmsDoTransform(hTransform, inputBuffer, outputBuffer, 1);


    cmsDeleteTransform(hTransform);
    cmsCloseProfile(hInProfile);
    cmsCloseProfile(hOutProfile);

 printf("Input values: cmyk( %d, %d, %d, %d )\n", inputBuffer[0], =
inputBuffer[1], inputBuffer[2], inputBuffer[3]);
 printf("Input values: rgb( %d, %d, %d)\n", outputBuffer[0], =
outputBuffer[1], outputBuffer[2]);
 return 0;=20
}

Re: [Lcms-user] XYZ16 --> RGB8 --> different XYZ16

[<ma...@li...>]

Hi,

Is correct ;-) This is a testimony of how destructive could be temporary
storage.=20

XYZ does exhibit a gamma of 1.0, sRGB a gamma of 2.2, if you converts =
from
a space of gamma 1.0 to an space of gamma 2.2, you get loss of data.

This effect is also magnified by the fact you are using 8 bits of =
temporary storage,
so, form 16 bit, gamma 1 to 8 bits gamma 2.2, there is a LOT of loss!

28589 ( 0x6FAD ) stored as 8 bits is 0x70 (by rounding),  28704 is =
0x7020,
rounding also 0x70. In your case, the 8 bits quantization is responsible =
of=20
these different numbers.

RGB8 --> XYZ16 --> RGB8 will work fine, since XYZ16 has enough =
precission
(16 bits) to recover the gamma loss.

Anyway, rare is the case of transforms completly reversible. If you are =
feeding=20
a profile with a color out of gamut, the profile will remap it on its =
own, depending
heavely on intent used. On in-gamut colors, the dance of numbers is =
minimized,
but, specially on perceptual intents, is not guarenteed forward and then =
reverse
will yeld same original values. sRGB does this and lcmslabi also do, but =
not all
profiles will behave same.

Regards,
Marti.
  ----- Original Message -----=20
  From: Richard Mitanchey=20
  To: Lcms-User list=20
  Sent: Wednesday, August 22, 2001 12:59 PM
  Subject: [Lcms-user] XYZ16 --> RGB8 --> different XYZ16


  Hi,
  I observed a strange behaviour with two kinds of transforms :
  * First, I tested RGB8 --> XYZ16 --> RGB8, and it worked fine, with =
the following numbers:
          (246,246,246)-->(28704,30197,32894)-->(246,246,246)
  * I also tried XYZ16 --> RGB8 --> XYZ16, and I got the following =
numbers
          (28589,30083,32768)-->(246,246,246)-->(28704,30197,32894)

  My profiles are :
          "sRGB Color Space Profile.icm"
          "LCMSXYZI.icm",=20
  and transforms parameters are :
          INTENT_ABSOLUTE_COLORIMETRIC, and cmsFLAGS_NOTPRECALC

  Am I missing something?
  Any clue?

  BTW: Just a few words to say that little cms appears to me the best =
ICM color management library for PC's
  Thanks again, Marti!

  Richard Mitanchey

[Lcms-user] XYZ16 --> RGB8 --> different XYZ16

[Richard M. <Ric...@en...>]
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Re: [Lcms-user] Problem running test on RH7.1

[Ashley M. K. <as...@pc...>]

Karl Heinz Kremer wrote:

> You have to link the testbed against the math library. Just add
> -lm to the linker flags:
>
> (From Makefile:)
>
> testcms: testcms.o ../src/liblcms.a
>         $(CC) $(CFLAGS) testcms.o ../src/liblcms.a -o $@ -lm

    Thanks, but...it already has that.

--
H | "Life is the art of drawing without an eraser." - John Gardner
  +--------------------------------------------------------------------
  Ashley M. Kirchner <mailto:as...@pc...>   .   303.442.6410 x130
  Director of Internet Operations / SysAdmin    .     800.441.3873 x130
  Photo Craft Laboratories, Inc.            .     3550 Arapahoe Ave, #6
  http://www.pcraft.com ..... .  .    .       Boulder, CO 80303, U.S.A.

Re: [Lcms-user] Problem running test on RH7.1

[Karl H. K. <kh...@kh...>]

You have to link the testbed against the math library. Just add
-lm to the linker flags:

(From Makefile:)

testcms: testcms.o ../src/liblcms.a
        $(CC) $(CFLAGS) testcms.o ../src/liblcms.a -o $@ -lm

Karl Heinz


On Mon, Aug 13, 2001 at 08:33:21PM -0600, Ashley M. Kirchner wrote:
>=20
>     After invoking install.gcc, it compiles, installs and then dives
> into the testbed and I get this:
>=20
> Building testbed...
> /usr/lib/liblcms.a(cmsgamma.o): In function `FGamma':
> /srv4/lcms-1.07/src/cmsgamma.c:61: undefined reference to `pow'
> collect2: ld returned 1 exit status
> done!
>=20
>=20
>     Anyone have a solution for this?
>=20
> --
> H | "Life is the art of drawing without an eraser." - John Gardner
>   +--------------------------------------------------------------------
>   Ashley M. Kirchner <mailto:as...@pc...>   .   303.442.6410 x130
>   Director of Internet Operations / SysAdmin    .     800.441.3873 x130
>   Photo Craft Laboratories, Inc.            .     3550 Arapahoe Ave, #6
>   http://www.pcraft.com ..... .  .    .       Boulder, CO 80303, U.S.A.
>=20
>=20
>=20
> _______________________________________________
> Lcms-user mailing list
> Lcm...@li...
> http://lists.sourceforge.net/lists/listinfo/lcms-user

--=20
Karl Heinz Kremer                                  kh...@kh...
PGP Key at http://www.freecolormanagement.com/download/khk.asc
EPSON Sane Backend:         http://www.freecolormanagement.com

[Lcms-user] Problem running test on RH7.1

[Ashley M. K. <as...@pc...>]

    After invoking install.gcc, it compiles, installs and then dives
into the testbed and I get this:

Building testbed...
/usr/lib/liblcms.a(cmsgamma.o): In function `FGamma':
/srv4/lcms-1.07/src/cmsgamma.c:61: undefined reference to `pow'
collect2: ld returned 1 exit status
done!


    Anyone have a solution for this?

--
H | "Life is the art of drawing without an eraser." - John Gardner
  +--------------------------------------------------------------------
  Ashley M. Kirchner <mailto:as...@pc...>   .   303.442.6410 x130
  Director of Internet Operations / SysAdmin    .     800.441.3873 x130
  Photo Craft Laboratories, Inc.            .     3550 Arapahoe Ave, #6
  http://www.pcraft.com ..... .  .    .       Boulder, CO 80303, U.S.A.

RE: [Lcms-user] How to convert RGB in some ICC profile to LAB

[Boris L. <b.l...@gm...>]

> I agree lcmsxyzi.icm and lcmslabi.icm are too big. If you can wait
just a bit,
> ver 1.08 is expected to be released on summer's end (middle
september).

Good news :-)

> New ver. adds the creation of sRGB, Lab and XYZ profiles "on fly", and
other
> major features, like scanner profile generation. The API remains same,
so you
> can experiment with the actual profiles, and all then change, humm..
say,
> "cmsOpenProfileFromFile()" to "cmsCreateLabProfile()" when 1.08 were
> available.

Thanks again for fast info.
yes, cmsCreateLabProfile() would be fine. Also I don't know if it is
easily possible make others (ie. HSV, ...)

And I will definitely wait for new release :-)

Boris Letocha

Re: [Lcms-user] How to convert RGB in some ICC profile to LAB

[<ma...@li...>]

Hi,

>I found in description of sRGB matrix which convert sRGB to XYZ and in
>your source is method how to convert XYZ to LAB. Is it good solution?
>Because I don't want to distribute these big ICC profiles with my
>application.

The matrix is not enought, since sRGB needs a gamma linear interpolation too.
Of course you can do the conversion process "by hand", but
is long and tedious, there are precission issues involved and is easy to
make mistakes. Also, without 3D interpolation  it will be very slow, and
I guess it is not worth all the work it deserves.

I agree lcmsxyzi.icm and lcmslabi.icm are too big. If you can wait just a bit,
ver 1.08 is expected to be released on summer's end (middle september).
New ver. adds the creation of sRGB, Lab and XYZ profiles "on fly", and other
major features, like scanner profile generation. The API remains same, so you
can experiment with the actual profiles, and all then change, humm.. say,
"cmsOpenProfileFromFile()" to "cmsCreateLabProfile()" when 1.08 were
available.

Marti.





----- Original Message -----
From: "Boris Letocha" <b.l...@gm...>
To: "Martí Maria" <ma...@li...>
Cc: <lcm...@li...>
Sent: Wednesday, August 08, 2001 9:50 AM
Subject: RE: [Lcms-user] How to convert RGB in some ICC profile to LAB


First thanks for answer.

I found in description of sRGB matrix which convert sRGB to XYZ and in
your source is method how to convert XYZ to LAB. Is it good solution?
Because I don't want to distribute these big ICC profiles with my
application.

BTW in libmng I found function how to create sRGB profile in memory so
it is IMHO good to include this function in lcms API also.

Boris Letocha

> -----Original Message-----
> From: Martí Maria [mailto:ma...@li...]
> Sent: Wednesday, August 08, 2001 8:08 PM
> To: Boris Letocha
> Cc: lcm...@li...
> Subject: Re: [Lcms-user] How to convert RGB in some ICC profile to LAB
>
>
> Hi,
>
> You need to use lcmslabi.icm or lcmsxyzi.icm as
> output profile. I do attach a sample on how to do
> the whole thing.
>
> Martí Maria
> The little cms project
> http://www.littlecms.com
> ma...@li...
>
>
> ----- Original Message -----
> From: "Boris Letocha" <b.l...@gm...>
> To: <lcm...@li...>
> Sent: Wednesday, August 08, 2001 8:18 AM
> Subject: [Lcms-user] How to convert RGB in some ICC profile to LAB
>
>
> I really searched hard, but cannot find such API function in lcms.
>
> Easier can be how to convert sRGB to Lab or XYZ colorspace.
>
> Thanks for any help.
>
> Boris Letocha
>
> _______________________________________________
> Lcms-user mailing list
> Lcm...@li...
> http://lists.sourceforge.net/lists/listinfo/lcms-user
>
>
>

RE: [Lcms-user] How to convert RGB in some ICC profile to LAB

[Boris L. <b.l...@gm...>]

First thanks for answer.

I found in description of sRGB matrix which convert sRGB to XYZ and in
your source is method how to convert XYZ to LAB. Is it good solution?
Because I don't want to distribute these big ICC profiles with my
application.

BTW in libmng I found function how to create sRGB profile in memory so
it is IMHO good to include this function in lcms API also.

Boris Letocha

> -----Original Message-----
> From: Mart=ED Maria [mailto:ma...@li...]
> Sent: Wednesday, August 08, 2001 8:08 PM
> To: Boris Letocha
> Cc: lcm...@li...
> Subject: Re: [Lcms-user] How to convert RGB in some ICC profile to LAB
>=20
>=20
> Hi,
>=20
> You need to use lcmslabi.icm or lcmsxyzi.icm as
> output profile. I do attach a sample on how to do
> the whole thing.
>=20
> Mart=ED Maria
> The little cms project
> http://www.littlecms.com
> ma...@li...
>=20
>=20
> ----- Original Message -----
> From: "Boris Letocha" <b.l...@gm...>
> To: <lcm...@li...>
> Sent: Wednesday, August 08, 2001 8:18 AM
> Subject: [Lcms-user] How to convert RGB in some ICC profile to LAB
>=20
>=20
> I really searched hard, but cannot find such API function in lcms.
>=20
> Easier can be how to convert sRGB to Lab or XYZ colorspace.
>=20
> Thanks for any help.
>=20
> Boris Letocha
>=20
> _______________________________________________
> Lcms-user mailing list
> Lcm...@li...
> http://lists.sourceforge.net/lists/listinfo/lcms-user
>=20
>=20
>=20

Re: [Lcms-user] How to convert RGB in some ICC profile to LAB

[<ma...@li...>]

Hi,

You need to use lcmslabi.icm or lcmsxyzi.icm as
output profile. I do attach a sample on how to do
the whole thing.

Martí Maria
The little cms project
http://www.littlecms.com
ma...@li...


----- Original Message -----
From: "Boris Letocha" <b.l...@gm...>
To: <lcm...@li...>
Sent: Wednesday, August 08, 2001 8:18 AM
Subject: [Lcms-user] How to convert RGB in some ICC profile to LAB


I really searched hard, but cannot find such API function in lcms.

Easier can be how to convert sRGB to Lab or XYZ colorspace.

Thanks for any help.

Boris Letocha

_______________________________________________
Lcms-user mailing list
Lcm...@li...
http://lists.sourceforge.net/lists/listinfo/lcms-user

[Lcms-user] How to convert RGB in some ICC profile to LAB

[Boris L. <b.l...@gm...>]

I really searched hard, but cannot find such API function in lcms.

Easier can be how to convert sRGB to Lab or XYZ colorspace.

Thanks for any help.

Boris Letocha

Re: [Lcms-user] Bug in type TYPE_ABGR_8?

[<ma...@li...>]

Hi,

Yes, is an incoherence solved in new revision, still unfinished.

TYPE_ABGR_8 is being rendered on output as BGRA_8,
just because windows likes it in such form. New revision will
fix this and add TYPE_BGRA_8 as well.

I hope to release new stuff on summer's end.

Martí Maria
The little cms project
http://www.littlecms.com
ma...@li...






----- Original Message -----
From: "Boris Letocha" <b.l...@gm...>
To: <lcm...@li...>
Sent: Wednesday, August 01, 2001 8:41 AM
Subject: [Lcms-user] Bug in type TYPE_ABGR_8?


It is defined as:
(COLORSPACE_SH(PT_RGB)|EXTRA_SH(1)|CHANNELS_SH(3)|BYTES_SH(1)|DOSWAP_SH(
1))

On input it use:
Unroll4BytesSwap

      wIn[3] = RGB_8_TO_16(*accum); accum++;  // K
      wIn[2] = RGB_8_TO_16(*accum); accum++;  // C
      wIn[1] = RGB_8_TO_16(*accum); accum++;  // M
      wIn[0] = RGB_8_TO_16(*accum); accum++;  // Y

On output it use:
Pack3BytesAndSkip1Swap

       *output++ = RGB_16_TO_8(wOut[2]);
       *output++ = RGB_16_TO_8(wOut[1]);
       *output++ = RGB_16_TO_8(wOut[0]);
       output++;

which is different functionality!

one of them is wrong...
From my position it is on input side because on Windows you have BGRA
and not ABGR.

Boris Letocha

PS: May be I am wrong, but please prove it :-)

_______________________________________________
Lcms-user mailing list
Lcm...@li...
http://lists.sourceforge.net/lists/listinfo/lcms-user

[Lcms-user] Bug in type TYPE_ABGR_8?

[Boris L. <b.l...@gm...>]

It is defined as:
(COLORSPACE_SH(PT_RGB)|EXTRA_SH(1)|CHANNELS_SH(3)|BYTES_SH(1)|DOSWAP_SH(
1))

On input it use:
Unroll4BytesSwap

      wIn[3] =3D RGB_8_TO_16(*accum); accum++;  // K
      wIn[2] =3D RGB_8_TO_16(*accum); accum++;  // C
      wIn[1] =3D RGB_8_TO_16(*accum); accum++;  // M
      wIn[0] =3D RGB_8_TO_16(*accum); accum++;  // Y

On output it use:
Pack3BytesAndSkip1Swap

       *output++ =3D RGB_16_TO_8(wOut[2]);
       *output++ =3D RGB_16_TO_8(wOut[1]);
       *output++ =3D RGB_16_TO_8(wOut[0]);
       output++;

which is different functionality!

one of them is wrong...
From my position it is on input side because on Windows you have BGRA
and not ABGR.

Boris Letocha

PS: May be I am wrong, but please prove it :-)

Re: [Lcms-user] Comparison between microsoft ICM and LCMS

[<ma...@li...>]

Hi,

Is same... only lcms has a lot more formats. lcms does support 16 bits per sample,
HiFi separations up to 16 channels, planar organization, swapped endian...
Even one can build new formats by using the provided macros.

Martí Maria
The little cms project
http://www.littlecms.com
ma...@li...

----- Original Message -----
From: Kevin
To: lcm...@li...
Sent: Monday, July 16, 2001 4:50 PM
Subject: [Lcms-user] Comparison between microsoft ICM and LCMS


I was just curious how the paInputColors and paOutputColors parameters for the TranslateColors function in Microsoft ICM compares
with InputFormat and OutputFormat of cmsCreateTransform, are they used for the same thing?
The Microsoft ICM accepts the following values:
typedef enum
{
    COLOR_GRAY       =   1,
    COLOR_RGB,
    COLOR_XYZ,
    COLOR_Yxy,
    COLOR_Lab,
    COLOR_3_CHANNEL,
    COLOR_CMYK,
    COLOR_5_CHANNEL,
    COLOR_6_CHANNEL,
    COLOR_7_CHANNEL,
    COLOR_8_CHANNEL,
    COLOR_NAMED,
} COLORTYPE;

While LCMS has a large selection of values it accepts for what seems to be a comparable purpose

-Kevin Koltzau