NEWS DE TOM HUFFMAN SUR AVS FORUM
Tom Huffman a testĂ© le lumagen avec la nouvelle technologie "125 color calibration"
Description and Review of Lumagen's New 125-Color Calibration Technology
3 hours, 16 minutes ago
I have spent quite a bit of time with the new Lumagen color correction technology that address a 5x5x5 matrix for a total of 125 colors. This is a really big deal for affordable consumer video calibration. For a description and review, see the ChromaPure New Gear page.
NEWS DU CEDIA 2012
SpectraCal Shows Radiance Color Cube Technology at CEDIA 2012
(Indianapolis, IN) â€“ September 5, 2012 â€“ Lumagen, Inc., designers of the Radiance series of video processors, announced the first color cube processing for home theater at the CEDIA Expo today. The processor is being shown in the SpectraCal booth, booth 1237 at the Indiana Convention Center in Indianapolis.
The color cube will allow more precise calibration to ensure the most accurate video image.
Color cubes are also known as 3D Look-Up Tables (LUTs), although the technology is unrelated to stereoscopic (aka 3D) video. Cube technology is currently used for characterizing high-end reference monitors in professional video production and post-production. Color cube correction has never been available to the viewer at home.
â€śThe new color cube processing in the Radiance is the first time the home user has been able to apply the same color correction technology as professionals who adjust color for a living,â€ť said Derek Smith, founder and CTO of Seattle-based SpectraCal, Inc.
Simultaneous with the availability of color cube functionality in the Radiance series, SpectraCal is releasing software to make use of the added levels of control. SpectraCalâ€™s CalMAN 5 automatically characterizes any video display and sets the Radiance appropriately to correct the displayâ€™s deviation from the standard.
The Radiance color cube technology allows settings at 5 points of luminance, saturation, and hue, for a 5 x 5 x 5 cube.
â€śThe 125 points of control ensure that nonlinearities in display technologies which could not be corrected by previous video processors can now be completely addressed by the Radiance,â€ť said Jim Peterson, Lumagenâ€™s President.
â€śItâ€™s amazing the difference in the quality of the video image before and after calibration with the Radiance 3D LUT,â€ť said Joel Barsotti, SpectraCalâ€™s Director of Software Development, who personally developed the Radiance implementation. â€śAfter calibration, every color is visually indisguishable from the reference standard,â€ť Barsotti said.
â€śEven though the 125-point calibration is much more precise, the calibration itself is actually much faster and easier,â€ť Smith said.
The color cube technology, still in pre-release testing, is freely available to current Radiance owners.
alex_t a Ă©crit:Une petite explication de Jim Peterson, le prĂ©sident de LUMAGEN: http://www.convergent-av.co.uk/forum/in ... #msg_19273Jim Peterson a Ă©crit:To my knowledge, all consumer level displays/projectors use the HLS color space for CMS. The HLS (or HSL if you prefer) is a non-linear color space and so is not mathematically correct for this calibration -- it's just easier to implement, which is why it is used I suspect. This means that even with a display/projector with linear response, using HLS color space means only the calibrated primary/secondary points are correct. Points in between are not correct.
The Radiance 8-point Gamut CMS uses a linear-Gamma RGB color palette. This means that if the display/projector has a linear response it can do an excellent job of calibrating CMS. However, if the display/projector has a non-linear response, such as red-push or green-push, interior points in the color cube need to be adjusted for correct response. With the 8-point Gamut, one can use Color Hue and their offset to mitigate red and green push, but this must be done by eye looking at real material since there is no easy way to automate it. It is tough to get this just right.
The new 125 point (5x5x5) linear-Gamma RGB color palette can correct for this and other non-linear responses, and should certainly give better performance than anything available in a consumer projector or display.
Note that the Radiance 11/21-point Grayscale is calibrated first. Then the 125 point CMS palette is calibrated. They are logically in series with the CMS first followed by grayscale
alex_t a Ă©crit:Il est lĂ (pour le XD ici: http://www.lumagen.com/testindex.php?mo ... ce_updates )Beta 090412- NEW 125 point CMS added! That's a 5x5x5 matrix for color correction and calibration. A big upgrade from our previous 8 point matrix which allowed calibration from only the corners of the color cube. The new 125 point gamut has it's calibration points located at 0, 25, 50, 75,100% of video min/maximums. The older 8 point gamut was located at digital min/maximums which did not give quite as much precision. Previous calibration values in the CMS gamut menu are interpolated to the new gamut locations so the numbers displayed in the menu will be different. This doesn't change your previously performed calibration results. Instead, the changed values represent the same calibration but from the new gamut locations. You now have the option of calibrating with 8 or 125 points. If you perform an 8 point calibration you can change to the 125 point mode and keep the previously set 8 points. The other 117 points are interpolated from the original 8 when changing from 8 to 125 point mode. With this many points to adjust, auto calibration software from ChromaPure and SpectraCal really helps. They have both added support for our new 125 point gamut with excellent results. Note: We are in the process of updating the Configuration Utility to support backing up the new 125 point gamut data to a PC via rs232. This should be available by tomorrow.
Gamma correction: Range has been extended and can now be adjusted in steps of .01.
Test Patterns: Added 2.35 letterbox geometry overscan pattern.
Bugfixes,etc: Problems with Top/Btm 3D formats to Frame Packed and Frame Sequential output was fixed. An issue of using test patterns with certain settings not restoring the input aspect was fixed. Improvement to output setup menu allows multiple changes within the command to be performed more easily. Added sending 601/709 color information needed by Darbee Darblets with firmware before 2.8.2214. Added a direct command to globally disable video on output 1, "menu 0985". Other small fixes and improvements were also made.
Quelques dĂ©tails sur l'implĂ©mentation de la mise Ă jour , source: http://www.convergent-av.co.uk/forum/in ... #msg_19282Jim Peterson a Ă©crit:You do not need to wait until your next calibration to update to the 5x5x5 software.
Patrick spent a lot of time making sure old 8-point, and grayscale, calibrations yield the same calibration points (RGBCMYW, and 11/21 grayscale calibration points) using the new 5x5x5 software. Note: If you did find any issues, you could always go back to older software and your old data will still be intact.
The new 5x5x5 CMS release uses the 5x5x5 FPGA-hardware for the 8-point CMS calibration. So, the software does need to interpret the old 8-point data and apply it to the new hardware. While this means there might be a very small chance of a significant measurable difference, we do not think there will be.
That said, there is an advantage to using the new 5x5x5 software with your old 8-point calibration. The new hardware has higher precision, and the blend of Grayscale and CMS has been improved. So while you should get the same measured calibration points, the image color accuracy will improve with the new 5x5x5 software using your old 8-point calibrations.
Credit where it is due: On the Lumagen side this improvement was due to Patrick's efforts for both software and hardware. While I did have some input on architecture, Patrick spent nearly a month (possibly more. I am not sure) on optimizations to allow this to fit in our FPGA, and on the actual implementation, and deserves the lion's share of your praise for the new 5x5x5 CMS.
And again thanks to both Spectracal and Chromapure on there input, software development, testing and feedback on this exciting new feature.
La mĂ©thode pour calibrer, source: http://www.convergent-av.co.uk/forum/in ... #msg_19284Jim Peterson a Ă©crit:Because the new 5x5x5 FPGA hardware works differently than the old 8-point calibration, there is a new order of steps for calibration.
Here is the new best practices order:
1. Set display controls to neutral and turn off all special features in the display (including dynamic-iris).
2. Set black level display controls. Use Radiance Dark-PLUGe for black (go to contrast pattern and press number 4 on remote).
3. Set white level in display being careful no color channel is crushing. Use the 2-white/2-black box contrast pattern and others.
4. Set 100% white color-of-gray in display using appropriate sized window pattern, if available.
5. Check Gamma and use Gamma factor for coarse Gamma adjust.
6. Recheck black and white and again use display controls to adjust them if Gamma factor changed them.
7. Calibrate Grayscale/Gamma with 11/21 point. Note, once any CMS entry is changed, do not tweak any grayscale entries!
8. Use CMS white point to reduce 100% white Luma only (R=G=B), if needed, such that RGBCMY have enough Luma.
9. Calibrate other CMS points.
This sequence works for both 8-point and 5x5x5 in the new software. The old procedure does NOT work properly with the new 5x5x5 software. Old 8-point CMS data does get interpreted correctly with new software as mentioned in previous post.
[EDIT] Interestingly, this new calibration sequence works with old software.
We will be updating our Tech-Tip 2 on calibration with the information soon.
source: http://www.convergent-av.co.uk/forum/in ... #msg_19285Randy Freeman a Ă©crit:The new Beta Software has been posted!
When you update your software, the old calibration will be accurately mapped into the new color cube. This feature has been tested by a group of beta testers.
MERCI A LA LUMAGEN TEAM
(reste plus qu'Ă tester maintenant)
les topics sur AVS forum :
- Description and Review of Lumagen's New 125-Color Calibration Technology
- Radiance 3D LUT (5x5x5 Cube) Calibration with CalMAN 5