DIY HDTV Calibration Software Overview: A Comparison of ColorHCFR, ChromaPure, and CalMAN



ChromaPure is a new entry into the calibration software game, coming from Tom Huffman, who is a very experienced ISF Calibrator. Designed to be easy to use, and to work with the CMS systems that are available to consumers in recent displays, I was eager to use it and see how the process, and results, compared to those from ColorHCFR.

The main difference you'll find between the two programs is that ChromaPure is designed with a workflow in mind: Get initial measurements from the display, correct the settings in a specific order, and then get another set of results to compare. Unlike the very free form workflow that exists in ColorHCFR, this makes it pretty easy to sit down and do a new calibration from Start to Finish, even if you have not done one before, and without constantly referring back to a web guide. Initially, you start by collecting a set of measurements for your grayscale and color gamut. As everything is influenced by the white balance and grayscale, it's what you really need to correct first, otherwise the colors will not be right, no matter how much you try.

The order that ChromaPure leads you through your calibration is: White Point, Color Decoding, Color Management, and Gamma. However, before you do either of these you should set the Contrast and Brightness of your display. Brightness is typically set using a PLUGE pattern, and if you have a light meter as you would when you use these programs, you can set the Contrast by determining the level of light you want from your display, and targeting that. For example, I wanted to get between 35-40 ftL from my Plasma, so it was easy to see even with plenty of light in the room, but not so bright that it was overpowering at night. Unfortunately, this PLUGE pattern and a segment to set this is one thing that ChromaPure is lacking, but when I gave this suggestion to Tom Huffman, he was very responsive to the idea, and it will be in a future version soon. You can set the Contrast by doing a continuous reading for 100 IRE in the Precalibration Grayscale section, but there is no PLUGE that you would need to set brightness correctly.

For the White Balance, on my Samsung I set a 30 IRE and an 80 IRE in the color decoder. The graphs that are provided in ChromaPure made this easy to hit, and the Red, Green, and Blue bars match up to the settings that you would adjust in a consumer CMS, which makes it easy to see where you are off and correct it. The measurement smoothing option is great as well, since readings will vary a little bit, and the average is really what you want to use at the end to get it right. Next up is Color Decoding, where you make the initial adjustments using Color and Tint controls. Some displays only offer these and not a full CMS, so these might be the only options you have to correct color, and in this case it will get you as you can with Red and Cyan, and hopefully that will help with the others. Thankfully, most displays are starting to come with more options, which you will use in the Color Management section.

Color Management will show you all the errors in your colors, broken down into Lightness, Saturation, and Hue, with the overall DeltaE (the overall error) for the color. Why this is far more helpful than in ColorHCFR is you can see where the error is for these elements, as this is how most CMS systems work to correct a color. Then you easily know what to raise, what to lower, and can see the results quickly as you work. Unfortunately, my Samsung uses a different model (R, G, and B values), which correspond to one of these items, but it varies by color and so it took a bit of work to get it done. Thankfully, when I mentioned this to Tom, he's going to include a toggle in the future for Samsung displays so that the readings will indicate R, G and B instead of Lightness, Saturation, and Hue, which would have cut my time down a bit. Overall, this was incredibly well designed, and easy to use, and I never had a question about what to do.

The Gamma section will let you see what the Gamma is for your display. If you can adjust your Gamma on a point by point basis, such as in the JVC RS25 that we used, then you can dial in the points individually, and on the RS25 it includes 5% and 95% values, which are used by that popular projector. As I just had a few set Gamma modes, I tried those and did a measurement until I got the one that was closest to 2.2, and there were no other adjustments that I could make. However, this was a limitation of my CMS, and not the software, and hopefully more displays will allow adjustable Gamma points in the future. I should point out that with version 1.2 of ChromaPure, it now has a built in pattern generator that let me use the HDMI output of my laptop to calibrate the display, and the software would automate taking readings with the meter as well, which made for a very fast, simple process.

Once this has been completed, you will take Grayscale and Color Gamut measurements to see how your previous settings compare to the updated settings. These are then available in a PDF report, either short or long, that you have for reference, or if you are calibrating for someone else, you have a report that you can leave for them. You can't adjust anything on this report, but it includes all of the data you are after, even if it is fairly long. My reports are attached, and you can see how much of a difference ChromaPure made with my display, and how accurate I was able to get it using the software and an i1 DisplayLT.

If you can't tell, I really loved using ChromaPure. It was simple, powerful, and fast. With the integrated pattern generation features, it sped up my calibrations by a ton, so that I could do one in under an hour without a problem. Tom Huffman was also very responsive, answering all of the questions that I had, and taking all of my suggestions to heart, including some in version 1.2, and letting me know that other suggestions will be included in future versions. The software is still very new, so there are some things missing that I would like to see (A sharpness pattern, a PLUGE pattern for setting brightness, and a more intuitive screen to help you set the correct peak output level for your display), but I'm sure those will be added as quickly as Tom can. If I was starting with nothing, and wanted to calibrate my own displays, I would purchase the i1 Display 2 with ChromaPure package, as it's an easy way to get started and get great results if your display gives you access to a full CMS.