CAT stands for Cromatic Adaptation Transform.
Chromatic adaptation means that the human eye performs an automated white balance. Colour is thus perceived by the human observer quite independently of the colour temperature; a white shirt looks the same white to us under fluorescent light as it does under incandescent lighting, a red rose is similarly red to humans under both lights.
The Cromatic Adaptation Transform (CAT) is a mathematical process in colour processing that simulates the adaptation of colour perception to different light sources. It is based on the natural phenomenon of colour adaptation, in which the human eye adapts to changing light conditions as described above in order to perceive colours consistently. In digital image processing, CAT is used to transform the colours of an image so that they appear constant under different lighting situations such as natural or artificial light.
CAT is used in colour science and image processing to harmonise the colour representation on different devices such as cameras, monitors or printers and to ensure uniform colour perception. For this purpose, the colour values are adapted to the conditions of a reference light source, usually the standard illuminant D65.
The most common CAT models, such as Bradford and von Kries, use different mathematical approaches to calculate the light adjustment. This process is particularly important in digital photography, for the colour calibration of devices and in image processing in order to ensure precise and consistent colour reproduction.
More articles related to this topic:
Colour deviations in 2023 PANTONE Color Bridge Guides
After Eddy Hagen pointed out in this posts, that there were some major colour deviations between the brand new PANTONE Solid Coated Guide 2023 and the previous version especially for the PANTONE 2635 C, I was curious to lookup the same colours in the new PANTONE Color Bridge Coated Guide of 2023 and compare the colours with the previous version. I measured a dE00 of 8,15 between the two colours that Eddy mentioned, which is really far apart from how accurate PANTONE colours should match between the different PANTONE guides. … read more
Incorrect grayscale display in Adobe Photoshop and InDesign
Adobe products are ideal for image retouching and layout and handle RGB and CMYK colour profiles very well. However, when editing and retouching grayscale images, for example for a black-and-white photo book, the experience is quite different. Suddenly, images look completely different in InDesign than they do in Photoshop, and even when exporting the image to PDF, greyscale images are suddenly treated differently. This article explains where the problems lie with black-and-white images and greyscale profiles in InDesign and Photoshop layouts, and how you can work in a more ‘colour-accurate’ … read more
Proof.de is featured twice in the “Fogra Aktuell” magazine
In the current issue of Fogra News “Fogra Aktuell” Proof GmbH is involved in two places. Firstly, a summary of the Fogra report on our first FOGRA55 certification for seven-colour printing with extended colour space in CMYKOGV appeared. You can also find more information on our FOGRA55 certification on the Fogra website: https://fogra.org/en/press-releases/fogracert-erste-cpc-zertifizierung-fuer-fogra55-cmykogv-330 and on proofing.de: And secondly, there was a report on the completion of the research project for textile digital printing, FOGRA58, in which we were allowed to investigate and test the proof capability of the new textile … read more
Proofs with Digimarc EAN codes and verification
Digimarc is a digital watermark that can be used to embed information in images, videos or other media. Digimarc watermarks are invisible to the human eye, but remain recognisable to special software or devices. Digimarc is becoming increasingly popular in the packaging sector in particular, as this technology allows the digits of the EAN barcode and more to be applied invisibly to all areas of the packaging. Digimarc and EAN barcode at the supermarket checkout When scanning at the checkout, the checkout staff do not have to search for the … read more
PANTONE surveys users online about product and service direction
Today I received an email in which PANTONE asked how it should orientate its products and services in the future. The users were asked which countries, industries and company sizes they come from, but also what PANTONE products should look like in the future and what customers would be prepared to pay for PANTONE services in the future. Question: How much can PANTONE services cost? PANTONE appears to be orientating itself on the PANTONE Connect prices: All price queries have the lowest price category < $ 7,- / month, i.e. … read more
New PANTONE Formula Guides with incorrect ink formulations
Several errors have crept into the new PANTONE 2023 fan decks. In both the PANTONE Solid Coated and the Solid Uncoated color fans, there are colours for which the new ink formulations are incorrect. In the PANTONE Formula Guide Solid Coated fan 2023, PANTONE 107 C and PANTONE 108 C have absolutely identical ink recipes, as well as PANTONE 113 C and PANTONE 114 C. As the colors differ, this cannot be the correct. Several errors in the PANTONE Solid Uncoated fan 2023 In the PANTONE Solid Uncoated fan 2023 … read more
New feature: Orders & individual items can now be reordered with a single click
From now on, it’s much easier and faster: in the Proof Shop, you can call up and reorder entire orders or individual proofs directly from your order history. This saves you from having to re-enter every detail and gives you the assurance that all settings will be exactly the same as last time. With just a few clicks, your proofs are reordered – reliably, easily and in no time at all. What exactly is new? You can find your order history in your customer account. There are two new options … read more
Cross-media colour management really works
Peter Jäger is an expert in colour management that reliably works across the boundaries of printers and monitors, web and print – essentially: cross-media.
MYIRO-9: New Spectrophotometer from KonicaMinolta in action
Over the last few months, we at Proof.de have been thinking about further improving our already very good colour measurement technology in terms of speed and measurement precision. Relatively quickly it became clear that only two devices would come into question: The KonicaMinolta MYIRO-9, the successor of the former FD-9, or the X-Rite ISIS 2 XL. The starting point: Since we at Proof GmbH have 5 proofing devices, the calibration of targets for profile optimisation is a time-critical undertaking for us. Therefore, we had been looking around for an upgrade of … read more
Fogra Colour Management Symposium 2026 in Munich from 24 to 26 February
The most important colour management event takes place every two years in Munich: the Fogra Colour Management Symposium. Once again this year, all professionals are invited to make the pilgrimage to Munich: two days of lectures, discussions and a Bavarian evening await participants. Matthias Betz, owner of proof.de, will also be there again: for many years, he has been taking advantage of the opportunity to exchange ideas with colleagues and friends, learn about new technologies, hardware and software, and talk to colleagues from Fogra, freieFarbe, GMG and many more. In … read more