Color Management and Advanced Color Correction. Miami Ad School- 2015

Transcription

1 Color Management and Advanced Color Correction Miami Ad School- 2015

2 What is Color and and Where it happens? 1- A property of Objects 2- A property of Light 3- Color happens in the Observer -Color is an event where all 3 variables above constitute a critical part of it. 2

3

4 Light Sources: -Black Body Radiators Define Color Temperatures Electric Discharge Lamps LightBulbs emit light and heat Computer Monitors

5

6 -The Color of White Blackbody Radiation Reflection and Transmission Tricromacy: Red Green and Blue (RGB) and the biology of the eye. Photoreceptors /Red,Blue,Green cones

7 Trichromacy defines it all!!

8 Additive Primaries: Adding equal amounts of Red,Green and Blue Substractive Primaries: Mixing equal amounts of ink- Yellow, Cyan and Magenta

9

10 The order for naming the colors just go along with the natural spectrum. so RYOBIG ( as in the rainbow) JUST BECOMES RGB The Subtractives are matched to their Additive counterparts, therefore we will always say CMY THIS WORKS AS A TIP: WHEN WE NEED TO RECALL MATCHING ADDITIVES AND SUBSTRACTIVES, (COMPLEMENTARY COLORS) WE HAVE RED-CYAN R G B GREEN-MAGENTA C M Y BLUE-YELLOW

11 Artificial Trichromats Colorimeters, Scanners, Cameras They see (capture) colors slightly different from the eye

12 RGB vs CMYK? RGB devices use sensors to capture the 3 primary colors, but printing devices must subtract colors from a white surface, therefore they use CMY and black (K) inks

13 Chromatic and Achromatic attributes of light and color: Achromatic: Brightness-refers to our perception of intensity of light Chromatic:Hue and Saturation Refer to the quality of light

14 Hue and Saturation: Hue is the attribute of a color that gives it it s basic name (Yellow, purple,orange,etc), by mixing the purest Hue with different levels of white, grey or black you will get the Tints, Tones and Shades of that color, respectively Saturation is the purity of the color itself or how far it is from neutral grey. A totally desaturated color ends up as grey.

15 ! Hue: A hue is the purest or brightest form of a color.hues are colors that have not been mixed with white,gray,or black.the twelve colors around on the outermost part of the wheel are hues.!! Tint The circle of colors next to the hues represent the tint of each hue.a tint is the hue mixed with white. The hue may be mixed with just a touch of white or with so much white that the hue is very faint.! Tone! Shade Tone:The next circle of colors represent the tone of each hue. A tone is the hue mixed with true gray. The hue mixed with any amount of gray is considered a tone of the hue.!! Shade: The inner most circle of co ors represent the shade of each hue.a shade is the hue mixed with black. Just as with the tines. the hue may be mixed with just a touch of black or withso much black that you are

16 Calibration and Profiling -Calibration reviews and establishes the behavior of a device -Profiling is the numerical way used to define the behavior of the device in a measurable and reproducible way. -The process of calibration leads, with the proper tools, to build profiles for all devices. In our case we are interested in obtaining and using profiles for Capture Devices (cameras, scanners), viewing devices (monitors in computers, cell phone screens,tv s etc) and for Output Devices (printers, Industrial Pre-Press and Press)

17 Monitor and camera calibrations We will use the Color Munki Display System and the Passport Color Chart for monitor and camera calibrations and profiling Camera Calibration with Passport Color Chart

18 Tutorials for color correction

19 Advanced Color Corrections Techniques Look for the menu Adjustments in Photoshop for: Hue-Saturation Color Balance Selective Color Match Color Replace Color Channel Mixer

20 Tutorials for Matching Colors and Replacing Colors -How to change the color of an object in Photoshop Using Color Range to make selections based on Color and then modifying that color -Photoshop Color Replacement Change the Color of a Dress with Photoshop CC using Color Range How to change Dress Color without changing Skin tone -Matching Colors in Photoshop -Selective Color vs Hue/Saturation in Photoshop

21 LINKS ( Continued) -Subscribe to the PHLEARN channel in You Tube. -Don t forget to check on Photoshop s Help ( Step by Step instructions) Color Wheel Tool to recall the complimentary colors is useful to have handy when working on complimentary color adjustments -The Color Wheel and How To Use Complimentary Colors In Photoshop

22 COLOR WHEEL SHOWING HUES, TINTS, TONES AND SHADES

23 Basic Workflow for image processing 1- Physical Adjustments (Properties): -Defining Document Size, Print Size, Resolution, Cropping Correcting Line paralax, -2- Cleaning and Retouching - Cleaning (Healing clone/stamp tool), Correcting defects, removing unwanted items, compositing ( if required by the project) 3-Adjusting Colors and SkinTone -Starting with general image adjustments, both Numerical and Subjective ( White and Black Points, Neutralization,Hue-Saturation, Levels, Curves, Color Balance) -Proceed with adjusting color of selected areas (Color Range, Color Replace, Matching Color, Selective Color) 4- Color Conversions for Web and Print - WEB: RGB conversions (Adobe RGB (A98) to srgb, ColorMatch RGB,etc) -PRINT: RGB to CMYK, Check Color Gamut, Proofing 5-Cosmetic Adjustments and finishing -Filters (Liquify, Proprietary filters, etc) - adjusting minute details (Finishing) -Sharpening for print

24 Color Conversions RGB Conversions for Web: Images coming from camera captures and/or scans as well as files obtained from RAW processing ( using Adobe Camera Raw, LightRoom, Capture One, RAW Processor, etc) should be created in Adobe 98 or bigger color spaces (PhotoPro), as to preserve as much original color information as possible. This Master File should be archived and backed up in one of the big color spaces. Today, the standard or capture profile is Adobe 98 (A98). Some specialized monitors are already able to show all this color gamut However, the Internet and most digital design is all being handled in srgb color space. Conversions are not straightforward, as some colors fall out of gamut and review by numbers for critical colors is essential. Print Conversions: RGB to CMYK For this case, special attention must be put on knowing the color profile for the output (printing) system to be used,for each specific case. However, the adoption of several standards, like SWOP or Sheetfed profiles, provide the basis for generic CMYK conversions, when an industrial printing system is going to be used. In the case of inkjet printers and other conventional color printers (like commercial photolab s printers like Noritsu,etc), a very good quality printing can only be obtained if the output profile can be obtained and assigned to the file to be sent for printing. See graphic representations of the Color Spaces for comparison.

25 Adobe 98 (greyed out) vs srgb color spaces Adobe 98 (greyed out) vs CMYK (SWOP)

26 A color space provides the definition for what color the numerical combination represents. Color spaces are akin to languages. A value such as 88/249/17 is given meaning by the color space in the same way as an otherwise random sound has meaning in a particular language. If our example of 88/249/17 is interpreted using the Adobe RGB color space, it is a vibrant, attention getting green. If, on the other hand, the same value is interpreted using the srgb color space, it is a pale, sickly yellowish-green. This is shown below, using colors as close to the actual values as most web browsers can display. (88, 249, 17) in Adobe RGB The same RGB value in srgb As you can see, it is important to know what language each component of your image processing system speaks. Your camera, scanner, monitor, and printer all talk different color languages. None of them map the same actual color to the same R/G/B value. Happily for us, the International Color Consortium has created a standard ICC profiles for how devices can communicate color information. Our printer profiles let your image processing program, such as Photoshop, know how to translate what you see on the screen to the printed page as accurately as your printer allows. Monitor profiles tell your operating system (if you are using a Mac + OS/X), or image editor how to display the picture accurately. A profile of your camera or scanner lets all the other steps in your workflow know how to interpret the original image.

27 Basic Convert vs AssignProfiles Depending on the type of conversions you do either of 2 things: Assign a profile or convert to a profile. It is not a simple concept and there are many variations that can happen. In general, f you need to tag an image with an specific profile without altering the color values( rgb numbers), then you use the Assign Command in Photoshop. If you need to change the image s color values into another color space while keeping the appearance as consistent as possible with the way it currently looks, you then use the Convert Profile, but for our purposes we can assume this very general approach: 1- Going from conventional conversions like from A98 ( topic file from digital cameras) to srgb for the Web, or from RGB to CMYK, you convert to the adequate output (Use Edit>Convert to Profile) 2-Assign profile is typically used if one file, for some reason, has no color profile embedded. This should not be a situation we will be encountering often these days (Use Edit>Assign Profile)

28 Local Printing Profiles (Specifically Epson 7880) can be downloaded from: Additional info for installing printing profiles in your computer and printing in Costco REMEMBER: WE NEED A CALIBRATED MONITOR TO HAVE A REFERENCE TO COMPARE THE PRINT AGAINST, OTHERWISE IT IS JUST GUESSING ALSO, SEE PDF DOCUMENTS INCLUDED!

29 INSTRUCTIONS TO GET and INSTALL THE PRINTING PROFILES: Go to and look for Costco #182 in North Miami You will find 2 profiles available for the Epson Printer, for 2 types of paper, Photo Satin Paper and Semi-GlossI. I suggest the Photo Satin, but it is totally up to you if want to print in Semi Gloss. Just GET THE RIGHT PROFILE!! then, download the.icc file and install it in you computer. Follow this initial path Mac OS X (all versions): If your account has administrative privileges, storing profiles in Computer>Library>ColorSync/Profiles, allows all users to use them. Some times the place to allocate the profiles is different, depending on the version of Mac OSX. Contact me if you have trouble. Restart Photoshop ( or the computer) to have the profiles available by the System. Once the profiles are available, use Photoshop to convert your RGB file using the Costco Profile ( EDIT> CONVERT TO PROFILE) and SAVE the file.. Once the image has the Costco Profile embedded, Remember to check the Proof Colors and the Color Gamut to make sure your file will print as you see it in your calibrated monitor. This is the file to submit to Costco Online. The same procedure can be done for just about every printing system across the USA that has published their printing profiles in drycreekphoto.com or any other site. Start by just asking!

30 How Humans React To Different Colors Did you know that green is used for night vision goggles because the human eye is most sensitive to, and able to recognize most shades of that color? People are often more productive in rooms painted blue. Pink makes us crave sugar. Red increases enthusiasm. Grey represents non-involvement, giving it a formal authority. More about the interaction of color and Design in the document : How humans react to different colors available for download on the private link provided to you.

31 BY ALL MEANS: Review the set of PDF documents available on the link provided, there is plenty of useful info for the present and the future of your explorations in color. Hope you enjoy them!! Jorge Parra Photography