Re: Is there an HDM CMM for MacOS or Windows7-8?
From: Roger Breton <graxx@videotron.ca>
Using IDEAlliance's SWOP2006_Coated3v2 profile:
50 0 0 (ACE) 50.12 41.69 42.48 14.22
50 0 0 (PatchTool) 50.30 41.68 41.78 14.63
50 0 0 (Argyll) 50.29 41.68 41.78 14.22
Hi, Below is result from Matlab's Image Processing Toolbox CMM for profile SWOP2006_Coated3v2.icc using Absolute RI. addressing Lab value: [50 0 0] CMYK = 0.5030 0.4168 0.4181 0.1462 This CMM employs tetrahedral interpolation. Harold ------------------------------------------ "Keep it simple, but no simpler!" ------------------------------------------
Is tetrahedral interpolation more involved, computationally? Best / Roger -----Original Message----- From: colorsync-users-bounces+graxx=videotron.ca@lists.apple.com [mailto:colorsync-users-bounces+graxx=videotron.ca@lists.apple.com] On Behalf Of Harold Boll Sent: Thursday, March 7, 2013 1:53 PM To: colorsync-users@lists.apple.com Subject: Re: Is there an HDM CMM for MacOS or Windows7-8?
From: Roger Breton <graxx@videotron.ca>
Using IDEAlliance's SWOP2006_Coated3v2 profile:
50 0 0 (ACE) 50.12 41.69 42.48 14.22
50 0 0 (PatchTool) 50.30 41.68 41.78 14.63
50 0 0 (Argyll) 50.29 41.68 41.78 14.22
Hi, Below is result from Matlab's Image Processing Toolbox CMM for profile SWOP2006_Coated3v2.icc using Absolute RI. addressing Lab value: [50 0 0] CMYK = 0.5030 0.4168 0.4181 0.1462 This CMM employs tetrahedral interpolation. Harold ------------------------------------------ "Keep it simple, but no simpler!" ------------------------------------------
Here is the output from SampleICC: Linear Interpolation: 50.29 41.68 41.78 14.62 Tetrahedral Interpolation: 50.29 41.68 41.78 14.62 The difference between using linear Vs tetrahedral was only in the fourth decimal, so I do not think that could be a cause. The interpolation technique will also not matter if the L*a*b* falls on the grid point of the table. The difference for ACE could be due to the math being done on the GPU? I think ACE uses the GPU if there is one available. Regards, Rohit Patil Color Science Engineer ONYX Graphics Inc. -----Original Message----- From: colorsync-users-bounces+rohit.patil=onyxgfx.com@lists.apple.com [mailto:colorsync-users-bounces+rohit.patil=onyxgfx.com@lists.apple.com] On Behalf Of Roger Breton Sent: Thursday, March 07, 2013 12:35 PM To: 'Harold Boll'; colorsync-users@lists.apple.com Subject: RE: Is there an HDM CMM for MacOS or Windows7-8? Is tetrahedral interpolation more involved, computationally? Best / Roger -----Original Message----- From: colorsync-users-bounces+graxx=videotron.ca@lists.apple.com [mailto:colorsync-users-bounces+graxx=videotron.ca@lists.apple.com] On Behalf Of Harold Boll Sent: Thursday, March 7, 2013 1:53 PM To: colorsync-users@lists.apple.com Subject: Re: Is there an HDM CMM for MacOS or Windows7-8?
From: Roger Breton <graxx@videotron.ca>
Using IDEAlliance's SWOP2006_Coated3v2 profile:
50 0 0 (ACE) 50.12 41.69 42.48 14.22
50 0 0 (PatchTool) 50.30 41.68 41.78 14.63
50 0 0 (Argyll) 50.29 41.68 41.78 14.22
Hi, Below is result from Matlab's Image Processing Toolbox CMM for profile SWOP2006_Coated3v2.icc using Absolute RI. addressing Lab value: [50 0 0] CMYK = 0.5030 0.4168 0.4181 0.1462 This CMM employs tetrahedral interpolation. Harold ------------------------------------------ "Keep it simple, but no simpler!" ------------------------------------------ _______________________________________________ Do not post admin requests to the list. They will be ignored. Colorsync-users mailing list (Colorsync-users@lists.apple.com) Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/colorsync-users/rohit.patil%40onyxgf... This email sent to rohit.patil@onyxgfx.com
Roger Breton wrote:
Is tetrahedral interpolation more involved, computationally?
It uses less computation. It uses dimension + 1 vertices of a grid cell. N-linear interpolation uses 2^dimension (ie. all of) the vertices of a grid cell. So that's a difference of 5 to 16 for CMYK->whatever, or 4 to 8 for RGB/Lab/XYZ->whatever
From a quality point of view the recommendation is to use simplex/tetrahedral interpolation for spaces that are "device like", ie. A->B tables typically, where neutral lightness changes are strongly correlated to equal changes in the input channels.
For spaces where a change in neutral lightness is correlated to one input channel while the the others remain about the same, the N-linear is recommended. This is the case for doing L*a*b*-> whatever, ie. a B->A table. For actual overall (optimised for speed) transforms, simplex/tetrahedral is usually used anyway, because it's the fastest (unless you are using GPU hardware texture mapping). Graeme Gill.
participants (4)
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Graeme Gill
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Harold Boll
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Roger Breton
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Rohit Patil