October 2022 - colorsync-users

[NEXT MONTH] Don't Miss Color and Imaging Tech at its Best~CIC30
by Roberta Morehouse 08 Nov '22

08 Nov '22

RECONNECT in person. CREATE new relationships. ENGAGE in the latest color science + tech! The IS&T Color and Imaging Conference is BACK in person, 13-17 November 2022-BACK, where it all began in Scottsdale, AZ. https://bit.ly/_CIC30 DISCOVER THE LATEST COLOR TECH APPLICATIONS Level up with 17 intensive courses and 3 FREE workshops* designed to allow a deeper dive into specific color arenas. Save 10% on 3+ Courses COURSES & WORKSHOPS: https://bit.ly/CIC30Courses_Workshops *Workshops included with Technical Program Registration DYNAMIC TALKS from EXPERTS in their fields Keynotes from Roland Fleming read PPP at Oxford; distinguished scientist at InterDigital, Erik Reinhard; University of Leeds academic, Vien Cheung; and evening talk from National Geographic science photographer and explorer Babak Tafreshi. SPEAKER BIOS: https://bit.ly/CIC30_Keynotes ROBUST PROGRAM filled with RESEARCH + INNOVATION Three days of programming featuring more than 35 oral papers, 20+ interactive papers, exhibits, and a demo session from leaders and experts in color science and imaging applications. RECONNECT & ENGAGE Connect with colleagues, establish new relationships during the Welcome Reception and Cactus Awards ceremony, and learn about innovation and new applications during the exhibit and demo session. PRELIMINARY PROGRAM: https://bit.ly/CIC30-Program Join us for a week of color-related courses, workshops, paper presentations, exhibits, and exciting conversations around technical and application topics related to color and imaging! LEARN MORE & REGISTER: https://bit.ly/_CIC30 Roberta Morehouse, CMP Communications and Marketing Manager Society for Imaging Science and Technology (IS&T) -imaging across applications- http://bit.ly/ImagingOrg LinkedIn https://bit.ly/IST_LinkedIn Twitter https://bit.ly/ImagingOrg_Twitter @ImagingOrg #CIC30

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hello test
by marouane mouhtadi 23 Oct '22

23 Oct '22

hello

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ColorSync behaviour on pure Gamma TRC
by Rémi Achard 12 Oct '22

12 Oct '22

Hi, I have been looking at some unexpected results coming from simple gamma profiles, as the ones you can generate via DisplayCAL synthetic profile tool. I found that the gamma curve is actually replaced by a piecewise linear segment + gamma curve using a parametric curve tag. I was wondering if there are any reasons for ColorSync to do that or if anything is wrong in my assertion of the situation. I saw that an earlier topic mentioned a similar issue in Aug 2019 ( https://lists.apple.com/archives/colorsync-users/2019/Aug/msg00005.html) but I'm not sure I understand how to reply to it directly so spinning this new thread. To inspect ColorSync transformations, I re-purposed an example Objective-C program converting image colour space from an older Apple Tech Note / Documentation and added some debug print to get the transform details of the ColorSync fragment. Some truncated output from a sRGB to AdobeRGB conversion (for demonstration purposes only), focusing on TRC handling. sRGB EOTF decoding part: "com.apple.cmm.ParamCurve3" = ( "2.4", "0.9478673", "0.0521327", "0.07739938", "0.04045", 0, 0 ); "com.apple.cmm.PureGammaOriginalTRC" = 0; AdobeRGB EOTF encoding part: "com.apple.cmm.ParamCurve3" = ( "0.4545455", 1, 0, 16, "0.006200788", 0, 0 ); "com.apple.cmm.PureGammaOriginalTRC" = 1; You can see the AdobeRGB 2.2 gamma is gone (notice the PureGammaOriginalTRC=1) and replaced with a piecewise curve. According to my tests, this happens for simple gamma curv tag as well as para tag with type 1. If I use a para tag of type 3 emulating a pure gamma, I can get ColorSync to respect the pure gamma. When I plug the numbers into a homebrew parametric curve implementation, it does match what is happening in ColorSync which lead me to believe this method of inspection is working. Any idea what is happening?

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Printing from Affinity Photo, Designer and Publisher
by Louis Dina 09 Oct '22

09 Oct '22

I have no problems printing from Adobe PS, Illustrator and Indesign and my prints match my soft proofs quite well, but I've been having trouble printing properly color managed images to my inkjet printer from Affinity products (Affinity Photo, Designer and Publisher). I like the programs overall, plus there's no subscription fee and free updates for life (all for $55 per module). So far, printing is one thing I do NOT like. Perhaps it is just me and I am missing something. I'm using a Macbook Pro and running Monterey 12.6. My Canon Pro-100 printer driver offers two color options...Colorsync and Canon Color Matching. I always select Colorsync, and use a custom printer profile I made.When I select FILE > PRINT, I have access to all the output controls I need...EXCEPT for *Rendering* *Intent* and *BPC*. The program allows you to do soft proofs using Perceptual, RC, Absolute, Saturation, and BPC, however, I don't see any access to Rendering Intents and BPC when printing. Can anyone who uses these programs tell me how to print properly color managed files, or provide a suitable workaround? Thanks, Lou

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CIEXYZ, nCIEXYZ, un-normalized CIEXYZ... oh my!
by Jeff Nova 08 Oct '22

08 Oct '22

>From the 4.4 spec: "Un-normalized CIEXYZ values for illuminant (in which Y is in cd/m2)" "nCIEXYZ values of the illuminant of the PCS, encoded as an XYZNumber" "nCIEXYZ of media white point." The ICC defines nCIEXYZ as "CIEXYZ values that have been uniformly scaled so that Y = 1,0 for the adopted white" I'm trying to convert XYZ to xy chromaticity 1931 diagrams, and it seems the fields I want to show all vary in their flavor of XYZ. Can anyone point me to any resources that can help us meet these conditions? I'm using the Colour-Science library <https://github.com/colour-science/colour> presently, and their simple *XYZ_to_xy <https://colour.readthedocs.io/en/latest/generated/colour.XYZ_to_xy.html>* function. Thank you in advance for any help you can provide! Very best, Jeff Jeff Nova Chief Executive Officer Colorhythm https://colorhythm.com Mobile: +1 510-710-9590 Main: +1 415-399-9921

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Standard Light A?
by Jeff Nova 06 Oct '22

06 Oct '22

I keep seeing "Standard Light A" in DNG metadata. Presumably this is just Standard Illuminant A? Just making doubly sure. - J Jeff Nova Chief Executive Officer Colorhythm https://colorhythm.com Mobile: +1 510-710-9590 Main: +1 415-399-9921

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Deep Dive into Color & Imaging w/ CIC30 Courses + Workshops
by Roberta Morehouse 04 Oct '22

04 Oct '22

Deep dive into color science and imaging with short courses and workshops led by experts from Netflix, RIT, Dolby Labs, NTNU, and HP +. <https://www.linkedin.com/feed/hashtag/?keywords=topics&highlightedUpdateUrn…> Topics range from the basics of color and imaging to HDR and Video to Psychophysics and experimental design-and everything in between. Save 10% on 3+ Courses in addition to early registration savings. Rates increase on 17 October! https://bit.ly/CIC30Courses_Workshops Workshops are FREE with the technical program registration. IS&T 30th Color and Imaging Conference (CIC30) Short Courses + Workshops: 13-14 November Tech Program: 15-17 November Scottsdale, Arizona https://bit.ly/_CIC30 Discounted student and group rates are available. *********************************************** A sampling of courses by topic ADVANCED DISPLAY CONCEPTS & TECHNOLOGIES NEW SC11 OLEDs, Quantum Dots, and Color Imaging Charles Poynton & Peter Palomaki, consultants APPEARANCE SC06 Measuring, Modeling, and Rendering Surface Appearance* James Ferwerda and Snehal Padhye, RIT COLOR SCIENCE AND IMAGING FUNDAMENTALS UPDATED SC09 Human Color Vision and Visual Processing from Optics to Perception Andrew Stockman, UCL Institute of Ophthalmology PSYCHOPHYSICS AND EXPERIMENTAL DESIGN SC12 Fundamentals of Psychophysics James Ferwerda, Rochester Institute of Technology QUALITY AND ASSESSMENT FOR XR NEW SC04 Understanding Quality in the Era of Extended Reality (XR) Chaker Larabi, XLIM - Université de Poitiers VIDEO AND MOTION PICTURE NEW SC14 Color Calibration and Color Rendition Considerations for LED-Based Virtual Production Stages Carol Payne and Chloe LeGendre, Netflix VIEW ALL COURSES BY TOPIC + LEVEL<https://www.imaging.org/Site/IST/Conferences/CIC/CIC2022/CIC_Home.aspx?Webs…> ****************************************************************** WORKSHOPS<https://www.imaging.org/Site/IST/Conferences/CIC/CIC2022/CIC_Home.aspx?Webs…> are FREE with technical program registration. W1 Facial Appearance, Rendering, Perception, and Measurement* W2 Research and Education in Material Appearance* W3 Color Grading for Digital Cinema * Courses and Workshops held as part of MANER 2022<https://prosjektbanken.forskningsradet.no/en/project/FORISS/288187?Kilde=FO…>. [https://ist.informz.net/ist/data/images/2022%20CIC/Misc%20Graphics_Images/M…]<http://ist.informz.net/z/cjUucD9taT04ODIzMjgwJnA9MSZ1PTkwOTE3MTcwMiZsaT03Nz…> ***************************************************************** Roberta Morehouse, CMP Communications and Marketing Manager Society for Imaging Science and Technology (IS&T) -imaging across applications- imaging.org <http://www.imaging.org> Connect with us on LinkedIn<https://www.linkedin.com/company/society-for-imaging-science-and-technology…> and Twitter<https://twitter.com/ImagingOrg> @ImagingOrg

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