Why is color Management Necessary?

1. color is a human perception. The eyes (and mind) perceive spectral information that is used as a basis for color sensation. The colors Green, Orange or Yellow for example, are just terms - but do not describe the spectral components of the reflected light of an object.

   Therefore, a kind of color language is necessary to describe the spectral components of a certain color, which is not discussable by people (as for example sky-blue, deep blue, ocean blue or pale blue would be). A language that describes all the colors visible for humans, with the words of a computer, needed to be created.

   This language is called Lab, where L stands for lightness and a and b for the color components. With Lab it is possible to describe a color very exactly. We are going to have a closer look on Lab later.

   

   As every imaging device has its unique way of processing color, there is a standard way of describing the characteristic color of each device. This helps to pass exact color information from one device to another within the whole workflow.

   Digital cameras, monitors and inkjet-printers are probably the best-known components of a digital imaging workflow. But did you know that software is the most essential part of your workflow?

2. What is color Management?

   color management describes the whole system in your computer that is used for a precise color communication between hard- and software. It is used for describing the input characteristics of your digital camera, for controlling the display of an image on your monitor or to set an exact printout of what you see on your monitor. It is also necessary to pass images from one software to another without having color-misunderstandings.

   color management is possible with both, Microsoft Windows and Apple Mac OS X. It has a long history with growing possibilities on each new version of operating systems.

   A few things should be explained for easier understanding of color management.

   Profile

   A profile can be compared to a little tag that is stuck to each picture and imaging device. These tags describe specific color both in RGB (for Red, Green and Blue), and in the specific color management-language. That way, computer and software know what realworld- colors (in Lab) are meant by the RGB-values of a digital picture.

   Moreover, profiles can also contain CMYK-values instead of RGB-values (e.g. for offsetprinting). As we stay in the pure RGB-workflow, we won't focus on CMYK-color spaces in this text.

   color Space

   Each type of camera has its own way of seeing colors, such as each type of monitor has its own way of displaying colors. Also, printers have their own range of printable colors, which varies from type, ink and paper. This range of colors is called color space. A color space describes all colors that can be processed by an imaging device.

   The most common color space is sRGB. It describes the average color space a standard monitor is able to display. Most digital cameras are able to capture in sRGB color space and most printers can also print out images correctly in sRGB. Still, there are bigger color spaces such as ProPhoto RGB, Adobe RGB 1998, Wide Gamut RGB.

   These color spaces are used when highest quality is needed. Still, for most purposes sRGB is the right choice.

   

   Image 1: Comparison between sRGB (inside, colored) and Adobe RGB (outside, wire-frame)

   Profiles can be embedded into images, which is necessary for color communication among imaging applications. Without an embedded profile, an application does not know what real world colors a file contains, as the naked RGB numbers do not have any relation to Labvalues.

   Sony's Alpha cameras can shoot either in sRGB or Adobe RGB mode. If you have set your camera to capture in Adobe RGB, it's clearly visible on the camera's monitor. Besides, images shot in Adobe RGB can be recognized by a _ at the beginning of the filename (example: image1234.jpg → sRGB; _image1234.jpg → AdobeRGB) If you are still unsure which color space you have chosen when taking the image, you can consult the EXIF information.

   

   Color Management in Sony Image Data Converter SR (IDC SR)

   You need to set only a few options for achieving a fine color management workflow. Please choose settings in menu and open the color management dialogue. You can choose the working color space in the upper part: If you choose sRGB, Adobe RGB or Wide Gamut RGB, IDC SR will always publish processed images in the desired color space. If camera settings is chosen, IDC SR will take the working space is set in the camera. It can be either sRGB or Adobe RGB.

   

   Below the working space, you can find the color settings for your monitor. The choice will strongly influence the appearance of images in IDC SR, so you should keep an eye on it and - from time to time - check if the settings are still ok. If you do not have a certain monitor profile installed on your system, please choose sRGB.

   In case your monitor was delivered with a generic display profile, please install this profile in your operating system and afterwards choose it in other monitor profile.

   For a highly professional workflow it is necessary to calibrate the monitor (and also the printer). Individual monitor profiles that were created with third party color management solutions can also be chosen in the monitor profile section of the color management menu.

   If the calibration was made correctly and the resulting profile is chosen in the menu, a very reliable color display quality in Image Data Converter can be achieved.

   Displaying colors Correctly in Different Imaging Software

   In case you like working with additional imaging software from third party manufacturers, please make sure that your color management settings in other imaging software match those set in the Image Data Converter to obtain a correct color display!