The Comparison Of ICC V2 And V4 Profile Based On Perceptual Rendering Intent

The common issue we have met during printing workflow is that the color of prints is different from the original manuscript, or they have huge color differences. That’s the reason why we need to introduce color management. Color management is a technology of color conveying to control and manage color data between all kinds of input devices, displays and output devises. The aim of color management is to let image keep the same appearance in the process of color dissemination and replication. So Internation Color Con has made a common profile format, which is the so called ICC specification. It is used in cross-media color management between different softwares and operating systems.ICC color management means to control and manage color dissemination and replication between different platform by using ICC profiles and the way of gamut mapping to get the desired destination color. Where, ICC profile is a format to record the information of data transform between source device color space and profile color space; gamut mapping can be reached by using four different rendering intent: perceptual rendering, saturation rendering, relative-colorimetric rendering and absolute-colorimetric rendering. In reality, the output device gamut is smaller than that of display, so some colors can show in display while cannot be printed. In order to solve this problem, ICC defined the four rendering intent combined with the real needs and requirements.In reality, perceptual rendering intent is suitable for figure and scenery images which focus on the performance of overall color. This thesis researches the comparison between ICC v2 and v4 based on perceptual rendering intent. In ICC specification v2, the conversions between the individual media and ICC connect space are constructed independently, which results in that different profiler creator have to assume different source gamut in connect space when creating output ICC profile. In order to eliminate this ambiguous, ICC v4 has defined perceptual reference medium gamut as a common reference gamut. After knowing the printing workflow, this experiment used Epson Stylus Pro 9910 as output printing devise. And then use software i1 profile and Heidelberg Color Toolbox to create ICC v2 and v4 profile in the small and large output gamut, which will be assigned to ISO 12640-2 test images and conduct paired comparison subjective experiment of 21 observers. The results showed that ICC v4 workflows are suitable for skin tone, saturation of sky and the dark tone reproduction. While as for those images with colorful, more kinds and the materials like ceramic or metal,ICC v4 results have no obvious results. What’s more, compared to the 8 natural images results, ICC v4 works better for the synthetic images.