Screen flickering and color blotches?

[ozero]

Hello,

I was just wondering if anyone else had the same issues with their NOOKcolor. The first is screen flickering where it appears to look fuzzy, especially when lowering the brightness. This doesn't always happen, but I've noticed it a few times.

Also, when watching movies or looking at images, in dark areas the colors tend to look blotchy/dithered. There's isn't a smooth transition between the colors.

For instance, I downloaded the following image (iPad 1024x1024 version) and set it up as my wallpaper. The darker top half looks pretty bad, with patches of blue that don't blend in well. Same goes for movies. Does anyone else notice this?

http://interfacelift.com/wallpaper_b..._sunlight.html

Thanks for any help in advance!

[ZeroTX]

The first thing I'd say is get a correct resolution image (this isn't an iPad and isn't 1024x1024). Re-sizing for display rather than actually resizing to true 1-to-1 pixels is always quirky, even on a high-powered Windows PC or Mac. Frankly, this seems to describe the problem you're referring to. As for movies, I've yet to read anything that says the NOOKcolor does movies well. Then again, I also think that watching movies on a hand-held device is moronic... I have a 46" TV at home, why do I want to watch movies on a tiny screen in my lap? I've had movie-capable laptops for 10 years and never once watched a movie on them.

Anyway.... I'm curious, but haven't seen or heard of these problems.

[coolbreeze]

Originally Posted by ZeroTX

The first thing I'd say is get a correct resolution image (this isn't an iPad and isn't 1024x1024).

What's the correct background image size for the NC?

[ozero]

Well, the resolution is close enough to iPad so I just go with it. I don't know the exact size since the wallpaper moves to the left and right when looking at the other home screens, but it's close enough. I don't think that has anything to do with the color dithering.

The flickering seems to be pretty constant when pulling up the menu using the small arrow at the bottom of the screen. When the gray screen overlay appears, it flickers. After making a selection, it goes away.

[SCION]

Originally Posted by ozero

...
The flickering seems to be pretty constant when pulling up the menu using the small arrow at the bottom of the screen. When the gray screen overlay appears, it flickers. After making a selection, it goes away.

I've noticed that as well at low brightness. Like you said, the gray screen overlay is where it's pronounced. I haven't experienced any other flickering.

[SCION]

Originally Posted by ozero

Hello,

...
For instance, I downloaded the following image (iPad 1024x1024 version) and set it up as my wallpaper. The darker top half looks pretty bad, with patches of blue that don't blend in well. Same goes for movies. Does anyone else notice this?...

I, too, use the iPad resolution wallpapers. I change my wallpaper on a regular basis using the images from the same website. I haven't encountered any that look bad. What about other images from the site?

[ozero]

Originally Posted by SCION

I, too, use the iPad resolution wallpapers. I change my wallpaper on a regular basis using the images from the same website. I haven't encountered any that look bad. What about other images from the site?

Well, it's more apparent with any dark images with color gradations (movies as well). It's like if you dropped the color on your PC from 32-bit to 16-bit. The following picture is what I mean, though it's not quite so pronounced on the NOOKcolor.

http://help.adobe.com/en_US/creative...gif_dither.png

It may just be that the display can't display that many colors, but wanted to check if anyone else thought it was particularly noticeable.

[SCION]

Originally Posted by ozero

Well, it's more apparent with any dark images with color gradations (movies as well). It's like if you dropped the color on your PC from 32-bit to 16-bit. The following picture is what I mean, though it's not quite so pronounced on the NOOKcolor.

http://help.adobe.com/en_US/creative...gif_dither.png

It may just be that the display can't display that many colors, but wanted to check if anyone else thought it was particularly noticeable.

I understand what you mean now.

Here's a thread with links to high quality video clips you can test.

https://www.mobileread.com/forums/sho...=107571&page=3

This is the link to one of the test files if you don't want to read the thread in its entirety (only 18MB):

http://www.mediafire.com/?oz0baqsy5sli8sf

[ozero]

Thanks for the links. I actually found and copied over those very movies just before your reply. For the most part, they look great. The dithering is still noticeable in certain shots (dark clouds in the sky, some of the darker shots in the Tron trailer), but it's not terrible. My guess is that it's a screen limitation and that I'm perhaps looking a little too closely.

I don't notice the effect on my iPad with the same movies, but it's not a deal breaker. The flickering worries me a little more, but I'll wait it out and see if anyone mentions it as well. There's a user on the B&N forum asking about it, but no one seems to have a response.

[SCION]

I saw the post that you were referring to on the B&N forum. His sounds like an extreme case if he's noticing the flickering while reading (should have exchanged it). I don't have that issue and I keep my brightness setting at 1/3 or less. I do use the night mode without noticing any flickering. Until you pointed out the gray overlay scenario I hadn't noticed it. I guess because I was looking for it.

[DuncanWatson]

Originally Posted by ozero

Thanks for the links. I actually found and copied over those very movies just before your reply. For the most part, they look great. The dithering is still noticeable in certain shots (dark clouds in the sky, some of the darker shots in the Tron trailer), but it's not terrible. My guess is that it's a screen limitation and that I'm perhaps looking a little too closely.

I don't notice the effect on my iPad with the same movies, but it's not a deal breaker. The flickering worries me a little more, but I'll wait it out and see if anyone mentions it as well. There's a user on the B&N forum asking about it, but no one seems to have a response.

That dithering isn't a screen limitation. That is an MPEG artifact due to the encoding. A higher speed or higher resolution video would help. I encode all of my videos at 800x488 and 24 frames per second, as long as the source can support it. The technical term for "dithering" in an mpeg stream is macro-blocking, if you complain about your cable feed, use that term so the techs write it up correctly. The NOOKColor screen has a higher pixel density, you will notice artifacts present in video because of it. It is the same reason images look sharper on it then on the ipad.

The nookcolor doesn't rescale images down for its desktop, which is a wee bit annoying. What I do is resize them on my PC before transferring them over. It is the best way to get quality images.

[French]

I was going to chime in to say that I think the Nook does video exceptionally well. They just have to be converted correctly to begin with. I'm very happy. I make sure to turn the brightness up prior to watching a movie but they play smoothly with great color, crisp and audio and vidoe are 100% in sync.

[LoganK]

Originally Posted by DuncanWatson

The nookcolor doesn't rescale images down for its desktop, which is a wee bit annoying. What I do is resize them on my PC before transferring them over. It is the best way to get quality images.

Unless I misunderstand, it will rescale images. When you select the image, you'll see the image shrunken to the size of the screen with a box around it showing you which part will be used for the background. If you click and drag in the middle of the box, you can move it around. If you click and drag the edge of the box, you can resize it.

No?