Nearly all Samsung Galaxy Note screens suffer severe gamma issues (black clipping). It is still not known whether or not this is a software or hardware problem, or both, but most are leaning toward it being a kernel-level software issue.
We have tried to report this issue to Samsung itself, AC, Engadget, Android Police, Phandroid, and quite a few others -- yet NONE of them have bothered to so much as acknowledge the problem.
I have also been asking everyone to report the issue to the same blogs and media outlets. PLEASE DO SO to help us gain traction on this issue!!!
The following links demonstrate the prevalence and severity of the issue:
1. XDA -- [Bug] AT&T NOTE (i717) Experiencing Screen Problem with Dark Images and Video
[Bug] AT&T NOTE Experiencing Screen Problem with Dark Images and Video - xda-developers
2. If nothing else, please read this thread and test your device per the instructions in the OP:
XDA -- Black Clipping test image and Poll for AT&T Note Owners
[POLL] Black clipping / black crush - xda-developers
IMPORTANT: If you have a Galaxy Note, run the gamma test yourself to see the issue. The gamma test image is all you need to accurately identify, acknowledge, and measure the problem.
Using the gamma test image:
On a properly calibrated display, there should never be a severe dropoff from grey to black between any of the numbers (21 down to 0). Instead, a proper display will show a smooth/gradual transition all the way from grey (21) down to true black (0).
The problem on the Note running GB roms (including stock) is that it shows grey all the way down to 1 before dropping off a cliff to true black at 0. In the i717 ICS leak, it looks like Samsung tweaked something (possibly just the contrast) to move that severe grey/black drop to between 7 and 6. In other words, they simply shifted the point where the severe black clipping (dropoff) occurs in the dark spectrum.
To see what the gamma test image is
supposed to look like, simply view it on any other decent display -- a different phone, laptop, PC, etc...
3. XDA -- Technical discussion regarding the same black clipping problem on the International Note (N7000) as well
Galaxy Note colour rendering issue: started working on it. - xda-developers