Hello,
I take lots of photos and at the moment have a Nexus 10 to store and view them on. I like the Nexus 10 but the colour reproduction is a bit 'washed out' compared to viewing the same photos on my laptop or MotoG phone.
I am wondering if my photos would look brighter and more colourful on a Nook HD+. Does anybody have both the Nexus and Nook - how do they compare?
Any opinions much appreciated.
garrypenny said:
Hello,
I take lots of photos and at the moment have a Nexus 10 to store and view them on. I like the Nexus 10 but the colour reproduction is a bit 'washed out' compared to viewing the same photos on my laptop or MotoG phone.
I am wondering if my photos would look brighter and more colourful on a Nook HD+. Does anybody have both the Nexus and Nook - how do they compare?
Any opinions much appreciated.
Click to expand...
Click to collapse
I don't have both but if you take your Nexus to the store you can browse photos from the web on each as they usually have free wireless at B&N that would let you test, providing you have a B&N nearby. That would let you see the difference yourself. I love the way pictures look on my HD+ but as I said earlier I don't have a nexus to compare it with.
My Nook HD plus still seems to look better than most of the tablets I have seen. This may just be a personal bias of course. Plus I only had to pay $100 for an open android tablet.
Sent from my BN Nook HD using Tapatalk
Don't know if it's too late, but thought I'd chime in here. I don't have a Nexus tablet, but I have had a Nexus One phone. I bought the HD+ specifically to use as a photo frame (highly recommend the Social Frame HD app). I find the colors on the HD+ to be very bright and vibrant, even more than on my computer. My photos really pop, now. Of course, I'm sure there must be ways to tweak with settings. But out of the box, I am really happy with the color saturation of the HD+, not to mention the high resolution. Hope this helps
Related
Loving the nexus 7 however I'm wondering is it me or does the screen overall color seem a little faded/washed out. I mean the images are crisp but it seems the color isn't very vibrant.. thoughts? Or do I have a bad unit?
Thanks so much
I found myself thinking the same thing. However the only comparison I have is the same background on my Galaxy Nexus. It could just be the GN being very saturated. I like that though and was a bit disappointed by the screen.
I find the screen to be great. However, I have an Evo LTE so the color saturation seems to be pretty similar.
Sent from my Nexus 7 using Tapatalk 2
The screen is great to me. Very clean and viewing angles are great.
Washed after update
The colors were fine, but I'm noticing that they appear washed out since the most recent update. I don't have a direct frame of reference since I updated, but I could swear that the colors aren't as vibrant as they were before. I also have an Evo 4G LTE and the N7 colors are less vibrant (something that wasn't too obvious before). I know they are different screens, it's just something that didn't bug me before.
Hi, could you please comment on how good is skin tone color reproduction. Thanks.
i thinked the same that the colors looks like a bit washed out / fade.. is this normal?
The colors on the S3 are vividly colored
Defiant81 said:
Loving the nexus 7 however I'm wondering is it me or does the screen overall color seem a little faded/washed out. I mean the images are crisp but it seems the color isn't very vibrant.. thoughts? Or do I have a bad unit?
Thanks so much
Click to expand...
Click to collapse
I agree. I think the default automatic brightness feature is a little dull. You should try to manually increase the brightness....that seemed to fix my problem.
Sent from my Nexus 7 using xda app-developers app
Compared to both my Galaxy Tab (original 7" 2010 model) and my Galaxy Tab 8.9 LTE, (both with PLS, Samsung's version of IPS screens), the Nexus 7 is indeed more washed out/dimmer. It's brighter than my Nook Color though.
But the colors are fairly accurate and the viewing angles are good. Hoping for a mod that increases auto-brightness levels a few notches, and a mod to adjust color temps/saturation and I'd be happy with it.
You reading this Supercurio?
This should make it easier to enable/disable NVidia's Tegra PRISM option for rooted devices only : market link
"Many of the images were noticeably washed out -- they looked like over exposed photographs with missing highlights, reduced image contrast, and weak colors," Soneira wrote.
But I was curious why these shortcomings weren't showing up in reviews -- and why Soneira seemed to be contradicting himself when he told me that the display itself was "high quality." So, I asked him to clarify this.
Here's what he said.
The LCD panel itself is excellent. Good luminance, high Contrast Ratio, excellent Color Gamut and Color Saturation. So the raw LCD display itself is great. The problem is that the factory calibration of the display parameters (generally performed via firmware) is way off (particularly the Intensity Scale) so the images that appear on this fine LCD display look washed out...the display produces washed out images and colors in spite of the fact that it has a display with excellent color saturation and contrast. Similarly, a great camera will take poor quality photos if it isn't properly factory calibrated.
He expands on particulars in the blog post.
There is about a 25 percent compression of bright image content, which is quite substantial. This holds for both the Gallery Viewer and the Chrome Browser. On some cheap displays this is done intentionally by the manufacturer because the compression actually makes them appear artificially bright. Here I think it's probably just incompetence by the manufacturer, which is too bad because they messed up a really nice display.
I also want to know about this. The contrast seems very low to me. This display can do better than what it's currently set at.
Wrong thread ?
Sent from my Nexus 7 using xda premium
I have some faith that when morfic makes a trinity kernel for the n7 that some of this will be rectified. Unfortunately, his order was held up. I guess the first step is to find out what code is tweak able in the kernel to actually do this.
Sent from my Galaxy Nexus using xda premium
I believe I saw a mod which corrected some of the Galaxy Nexus dislpay shortcomings by calibrating it a bit differently. I wonder if the same could be said for the Nexus 7. @piam, I don't know why the reviewers never mentioned this in their reviews, but that's the first thing I noticed when I opened up my Nexus 7, and that was on the stock wallpaper that was on.
I just hope that someone gets a mod out soon, cause its a really great tablet looking cheap just because of the washed out colours.
I find that the home screen is not well optimized but Netflix is looking pretty good. I also find that lowering the brightness helps...which does indicate a calibration issue.
Its pretty good already though...almost quibbling.
Sent from my Galaxy Nexus using xda premium
mike infinity said:
I find that the home screen is not well optimized but Netflix is looking pretty good. I also find that lowering the brightness helps...which does indicate a calibration issue.
Its pretty good already though...almost quibbling.
Sent from my Galaxy Nexus using xda premium
Click to expand...
Click to collapse
I've noticed while using YouTube as well. If play videos on my Galaxy Nexus side by side with my Nexus 7, the colors look washed out. Probably there will be a kernel fix.
christophermx4 said:
I've noticed while using YouTube as well. If play videos on my Galaxy Nexus side by side with my Nexus 7, the colors look washed out. Probably there will be a kernel fix.
Click to expand...
Click to collapse
Hopefully software can fix it, if it's a firmware problem.
Anybody knows about today status ?
We need official or not official update for our nexus 7 device!
Asus must give us possibilities for change white color compession!!!
christophermx4 said:
I've noticed while using YouTube as well. If play videos on my Galaxy Nexus side by side with my Nexus 7, the colors look washed out. Probably there will be a kernel fix.
Click to expand...
Click to collapse
Well it would, the GN is oled which would make any lcd look rubbish
Sent from my Nexus 7 using xda premium
I just received my Google Nexus 10 yesterday. After reading all the great reviews about the video quality I must admit I was shocked how poor it was. Don't get me wrong, it isn't awful by any stretch. The detail is certainly there and there is so much detail it might actually be detriment to the product because I can pick up compression artifacts and pixelization I didn't even know was there on some of my videos. However, this really leads in to what I think the source of the problem is on this device, that is, the black level. The first video I took a look at was Ice Age since it came with the N10. If black level is off on animations they can look washed out and it certainly did in this case. My projector on a 100" screen could actually reflect a better image in my opinion. Moving over to other videos like a 1080p MKV of Battleship displayed some improvement, but the poor black levels were still there. Oh, and I should mention this was with using MX Player.
So, are others seeing something similar? Again, I'm not trying to really downplay the image entirely because the detail is certainly there, but again, I'm disappointed by the black level. Is there possibly a way to adjust it that I'm not aware of? All I can seemingly find is Brightness and that doesn't do enough. Perhaps a gamma control would help? Any guidance from others is appreciated.
U get ice age free with N10?
Sent from my Nexus 10 using XDA Premium HD app
verusevo said:
U get ice age free with N10?
Click to expand...
Click to collapse
Yes.
2 posts? Troll?
Techie2012 said:
2 posts? Troll?
Click to expand...
Click to collapse
Thanks for the welcome. Did people say the same about you when you had 2 posts? Trust me, your accusation is utterly ridiculous. This is simply my first Android device and this was my initial impression. I hoped that there might be some kind of workaround or fix so I simply did a Google search for a Nexus 10 forum and wound up here. As I allued to in my initial post there are plenty of things I like about the device and black level might not be a deal killer, but if there was a way to resolve it, why not pursue it?
Techie2012 said:
2 posts? Troll?
Click to expand...
Click to collapse
Only 245 posts and a member since February of this year? You must clearly have very little to contribute anywhere since you don't have at least a 1k post count or year+ membership (sarcasm btw; post count and join dates means absolutely nothing in determining a person's status lol)
I believe a few others have mentioned black levels not being optimal on the N10. I myself don't really see it as a problem, but then again I rarely watch videos. I believe Contrast itself might be a better option to modify over Brightness, but I'm pretty sure Contrast isn't adjustable currently.
Possibly when Kernel development matures enough, we may be able to modify screen settings, but I don't think we're there quite yet. Maybe some video players might have an option for adjustments?
Those frequenting here have varying social skills. Be tolerant.
Suggest posting some pics of screen's black level, alongside another device used as a baseline. A thousand words and all that.
Also suggest searching Play store for "display settings" and try out the various widget/apps available.
That's seriously put me off buying this tablet now.
A poor black level can ruin video quality. I know this because my laptops black level is shocking bad, picture below.
Now I might either get a Note 10.1 or wait for something with a high res screen and a good black level.
Haha you guys are funny.
Anyway back to the original question, this device has a LCD screen, and like most LCD TVs, the black is not as black as you'd like or you would see on a PlasmaTV or Amoled screen.
If black levels are highly important to you, i'm sorry to say you bought the wrong device.
Ok, so I took a previous poster's advice and got a hold of an iPad3 with Retina Display and compared it against the N10. The difference was not as significant as I thought it might be. Ultimately, I didn't think either producing razor sharp images with inky blacks and that is because they don't my own HDTV's (LED) in my home along with my home theater projector crush both devices. Why? Well, first, I wasn't aware that the contrast ratio was so poor on all the tablet devices. Most of my other products have something like a 50,000:1 contrast ratio whereas the tablets are around 1000:1, a very big difference. Also, I'm accustomed to watching BluRays on those displays. BluRay quality just doesn't seem to exist on these tablets right now. So was I expecting too much from the N10? Yes.
Spending some time with both devices side-by-side allowed me to sort of critique both on my own terms and decide which one I like best. I'm probably an atypical user so my opinions here are my own and I don't expect others to find the same items valuable.
1. Display - the iPad wins here, but not by as much as I might have thought. Whites are more warm and not as bright on the N10 when compared to the iPad. Blacks are also better on the iPad, but I expected it to be a dramatic difference. It wasn't. I've included some images to this post that will help you see the difference a bit more. There are some images where the difference looks very pronounced, but that is the digital camera really exposing the faults of the N10 and making them appear more significant. I wouldn't say that is the case in reality. Also, something you'll notice from the images is the light leak. It is there on the N10, but not on the iPad. Too bad Samsung couldn't have done a better job here. It would have made it appear as a more quality product.
2. Form Factor - I find the form factor of the iPad better than the N10. I like to use portrait mode more often than most I think and the iPad gives you more space to work from horizontally when doing so. This makes web browsing much easier and I actually feel more cramped using the N10 to browse via landscape. I would MUCH prefer the N10 to have the iPad's shape.
3. Weight - I would have never thought 50 grams or whatever it is would make a difference, but to me it does and the N10 is a clear winner here. After handling both devices for some time I simply enjoyed holding the N10 more. The lightness made for a more enjoyable experience.
4. Rubber Backing - When I saw on this on the N10 I thought it was sort of a gimmick, but I really like it. Again, it just seems to feel more comfortable holding it.
5. Heat - I have no idea why, but the back of the iPad got pretty hot while using it. The N10 had some slight warmth, but ever since I've used it it has stayed relatively cool.
6. Speakers - The N10 really crushes the iPad here. The front two speakers are awesome and can push out good volume. Going back to the iPad with its rear mono speaker almost feels silly in comparison.
7. Web Browsing - The winner here is the iPad. Pages came up more quickly, they are easier to scroll through (only slightly), and are displayed better. In portrait mode the clear winner is the iPad since you have more horizontal space to work with, something I like.
8. Off-axis viewing - Not that you ever really need this because tablets are really made for a one person audience to be looking at the device head-on, but I did notice it. For whatever reason the iPad had a better image once you move off-axis from the device. The N10 was washed out more quickly as you moved off-axis.
9. Bugs - Oh man, Jelly Bean has them. I have essentially the base image on the N10 and I've already seen the battery information incorrect (stuck), freezes, my folders just disappearing after the device becoming frozen, and some other very quirky things. The iPad in comparison was stable. The iPad just feels a bit like driving a Lexus. It doesn't really do much to excite you, but it does what it is designed to do and does it well. The N10 is probably more like a BMW X6. Is it a sports car or an SUV? No one really knows. It does some things that are really neat, but in other categories it sort of falls apart. Just my own silly analogy.
So which will I keep. Based on all the criteria above I would say it is very close and probably a tie in my mind, but I'm leaning toward the N10. I'm not sure why, but I struggle a great deal with going to a closed environment like the iPad is. It feels boring to me and I just think I might enjoy tinkering with the N10 more. If I give it more thought I might change my mind, but for the moment this is where my head is.
I hope all this might help someone. If anyone has any questions about the comparison or the images please feel free to ask.
A lot people seem to crank the brightness even when they don't need it. The N10 with the back light turned up definitely has poor black levels but it's actually pretty decent when below 40%(more comfortable to view also)
I agree. I'm totally unimpressed by the video quality of Nexus 10. Maybe I'm doing something wrong here, but my older Galaxy Tab 2 P3100 had much better video quality than this. The colors are totally messed up and the it just seems bland and boring.
Frankly, I don't think this is an iPad killer in anyway, and I'm not an apple fanboy either. I had to download apps just to get the Volume to a reasonable level eventhough it has stereo. Wow, the ipad claims much less but delivers more, Nexus 10 claims tall but falls short.
Thinking about getting back the iPad 4 if the Nexus doesn't grow on me. Sorry, Nexus. Android has failed you :crying:
JPW1 said:
Most of my other products have something like a 50,000:1 contrast ratio whereas the tablets are around 1000:1, a very big difference.
Click to expand...
Click to collapse
The 50,000:1 contrast ratio is actually dynamic contrast ratio. How dark the screen is at it's lowest brightness and how bright the screen is at it's highest brightness. It's really just a marketing gimmick.
The real static contrast ratio could be anywhere between 1000-5000:1. Not a huge difference at all.
http://www.dslreports.com/forum/remark,23137918
Looking at your screenshots I can definitely say you have the brightness set waaaayyy to high on the Nexus 10. Turn it down and the picture will be drastically better.
And for the other little problems you have to wait some time. Most of them will be gone with the first good custom roms/kernels. The device is still brand new.
I tried both the Transformers and Ice Age films streaming from google play, and I thought the video was pretty poor. Wifi signal was strong.
Video quality from all the streaming services I've used on Android have relatively poor quality. If you are attempting to benchmark the device's fidelity then I suggest making a high bit rate rip of a Blu-Ray
The high bit rate 1080p and 1440p videos I've seen look pretty great, but I agree videos from streaming services look pretty awful in terms of both blurriness and contrast.
Also, the hardware decoders like most devices do not have as high of picture quality as some software decoder. For instance, for the same video the hw decoder will look softer than the sw decoder in MX Player
Anyone else notice this? I took some pictures comparing my iPad Mini (left) vs Nexus 7 2013 (right). The first attachment is from YouTube F4bnVZmdOKs @ 5:31 - notice the splotchiness in the darkest areas. The second is from G-R8LGy-OVs @ 3:56 - notice the halos around the stars. When I watch on my computer (HP LP2065 IPS LCD) it looks much more like the iPad's display.
Looks like video compression blockiness that you don't see on the iPad because of the horrible black levels. If you look at a black still picture do you see the splotches?
Dimethyl said:
Anyone else notice this? I took some pictures comparing my iPad Mini (left) vs Nexus 7 2013 (right). The first attachment is from YouTube F4bnVZmdOKs @ 5:31 - notice the splotchiness in the darkest areas. The second is from G-R8LGy-OVs @ 3:56 - notice the halos around the stars. When I watch on my computer (HP LP2065 IPS LCD) it looks much more like the iPad's display.
Click to expand...
Click to collapse
I agree with the above poster, the splotchiness is video compression artifacts, and if you look past them, and take a step back, you'll actually see that you're getting much more detail and a better gamma on the N7 vs. the iPad. On the iPad side, the woman is completely black, yet on the N7, you can see her face and clothing detail that are simply missing on the iPad.
I would guess that the halos around the stars are similarly missing information on the iPad. With the N7, you're getting the whole picture.
That ipad mini picture is terrible. Talk about crushing blacks. ..... Look at the detail in the nexus picture. I hope your TV is not calibrated like the mini.
Sent from my SAMSUNG-SGH-I337 using xda app-developers app
I think its due to the high DPI. Try any HD video.
Actually the iPad Mini is quite terrible with the loss of dark details.
oh god that ipad looks awful dude.
Sent from my Nexus 7 using Tapatalk 4 Beta
there's probably a video player out there that supports gamma adjustment if it's not to your liking.in a specific video. it's hard to tell from that picture how black crushing the ipad is but some would find it looks "better" when the video is of poor quality. one thing you might want to do is adjust the backlight first (no need to do it global if you've got something like mx player) as the new N7 is supposed to be very bright. in the old n7 you can get away with making mx player always use max brightness because the maximum brightness isn't very high.
Good points. I attached a comparison of the black level test from Lagom. On the Nexus 7 I can see the 1 square easily. On the iPad Mini I can see the 5 square fairly well and the 4 just barely (IRL; hard to tell from the picture). The brightness setting for this and the previous comparisons was 25% on the Nexus 7 and around 55-60% on the iPad Mini. The subjective brightness was similar.
I borrowed an iPad 3 (Retina) to do some more testing. This time to eliminate any variables with video streaming I downloaded the 720P MP4s on my computer and captured stills with VLC. I used Chrome on both Android and iOS to view the images. Same videos as before, roughly the same scenes. The first 2 attachments show the comparisons: iPad 3 on the top, and Nexus 7 2013 on the bottom.
The 3rd attachment is the black level test on the iPad 3. I can clearly see square 2 and if I stare enough I can faintly detect square 1 (IRL; hard to tell from the picture again). The 4th attachment is a comparison of a full white image to show that the brightness is matched fairly closely (easier to tell if you convert to greyscale to ignore white balance differences) - 25% on the Nexus and just a hair above 50% on the iPad.
The 5th and 6th attachments are the source images I used for testing. I converted from PNG to JPG to make the attachments fit, not that it matters much since it's from a lossy source.
I still get the feeling that something isn't right about the way the Nexus looks. I was able to simulate the effect almost identically by applying gamma correction of 1.6 in IrfanView. That would seem to indicate that the Nexus's gamma may be way off, but after I finally found a way to view Lagom's gamma test image without scaling on the Nexus it looked pretty much spot-on correct. It it possible that only the very dark areas are "shifted" in a way that wouldn't affect the gamma test image?
This leads to the last attachment - a new black level test on the Nexus. Again, the brightness was calibrated similarly to the iPad, and the camera was set on full manual mode with all the same settings, so you can directly compare it to the iPad black level test image. Notice how the squares get brighter way faster than on the iPad? It's a lot more pronounced in the darkest squares, but the difference shrinks by the time you get up to the 40 square (last one before full white).
For my final test, I took pictures of Lagom's contrast test image on the Nexus 7 2013 and iPad 3. I then applied a Gaussian blur, converted to greyscale, and determined the RGB value for the first 13 bars. The first attachment is a chart of the results. The brightnesses converge around the 10th bar (RGB = 79 in the source image), but before that the Nexus's brightness is inflated. This explains why the gamma test looked fine, because even in the 10% luminance test, the RGB value of the ideal point is 88. The 2nd and 3rd attachments are the Nexus and iPad (respectively) displaying the test image.
you should bring all this to the "yellow tint" thread. this is a nice showcase on what's wrong with Nexus screen.
I recently purchased an X-Rite i1Display Pro display calibrator. I used it to make really accurate luminance measurements* of the Nexus 7 (2013) and iPad Mini while displaying shades of gray from 0 to 255 in steps of 5. I then calculated the effective gamma** at each step to create the attached chart. It also includes the effective gamma of the reverse sRGB transformation.
My conclusion is that the Nexus is fine if sRGB is the ideal target. I'm not sure what the ideal target is though; in fact, I don't really think there is one. A display gamma calibration of 2.2 to 2.4 seems like the most common recommendation. But almost everyone ignores the fact that sRGB's effective gamma is a lot lower in darker areas. I get the feeling that most people calibrate to a fixed target. sRGB is probably more technically correct. But if fixed 2.2 to 2.4 is more common, does that make it a de facto standard? E.g. if professional movie studios edit their movies on monitors calibrated to fixed gamma, but I watch it with sRGB gamma, doesn't that mean I'm not viewing it as intended by the creator? I'm not saying this is necessarily the case. I'm really, really confused .
So anyway, I just wanted to share my results. You will have to draw your own conclusions.
* I used spotread.exe from Argyll with the -x swtich. The first number from the "Yxy" result is luminance in cd/m^2.
** Effective gamma meaning: the gamma value you'd have to use to get the same luminance value from the input value. Formula is log(luminance) / log(input), where luminance and input are percentages from 0 to 1. I adjusted the luminances to account for non-perfect black levels.
mannequin said:
you should bring all this to the "yellow tint" thread. this is a nice showcase on what's wrong with Nexus screen.
Click to expand...
Click to collapse
I would say the iPad is just warmer (red) and the N7 looks more cooler (greenish-blue) Not by much though, just a few degrees off. No one device is perfect.
With the dark areas, it seems the brightness and/or gamma is too high. I use my screen at half brightness which seems on par with other devices and haven't noticed a big difference.
Hopefully we get a screen calibrator like on the N4 and can make adjust individual adjustments.
Sent from Nexus 7 FHD from XDA Premium HD
Dimethyl said:
My conclusion is that the Nexus is fine if sRGB is the ideal target...
Click to expand...
Click to collapse
all the measurements that you did are only true to the device that you own. the screens in the wild would differ (sometimes drastically) from yours and from one another.
I totally agree with you. I also see lots of artifacts with any dark scene on my 2013 Nexus 7. It doesn't matter if I am playing a higher resolution (HD) scene or lower resolution one. I wish there was a way to fix that.
Dimethyl said:
I recently purchased an X-Rite i1Display Pro display calibrator. I used it to make really accurate luminance measurements* of the Nexus 7 (2013) and iPad Mini while displaying shades of gray from 0 to 255 in steps of 5. I then calculated the effective gamma** at each step to create the attached chart. It also includes the effective gamma of the reverse sRGB transformation.
My conclusion is that the Nexus is fine if sRGB is the ideal target. I'm not sure what the ideal target is though; in fact, I don't really think there is one. A display gamma calibration of 2.2 to 2.4 seems like the most common recommendation. But almost everyone ignores the fact that sRGB's effective gamma is a lot lower in darker areas. I get the feeling that most people calibrate to a fixed target. sRGB is probably more technically correct. But if fixed 2.2 to 2.4 is more common, does that make it a de facto standard? E.g. if professional movie studios edit their movies on monitors calibrated to fixed gamma, but I watch it with sRGB gamma, doesn't that mean I'm not viewing it as intended by the creator? I'm not saying this is necessarily the case. I'm really, really confused .
So anyway, I just wanted to share my results. You will have to draw your own conclusions.
* I used spotread.exe from Argyll with the -x swtich. The first number from the "Yxy" result is luminance in cd/m^2.
** Effective gamma meaning: the gamma value you'd have to use to get the same luminance value from the input value. Formula is log(luminance) / log(input), where luminance and input are percentages from 0 to 1. I adjusted the luminances to account for non-perfect black levels.
Click to expand...
Click to collapse
Wow....I just look at my screen. It looks nice.
Not sure WTF all that shizz you posted is about. 250 device = 250 device. /shrug
Mine's right about fine xD .
The Nook HD+ has a very strong yellowish tint which makes all photos look like they've been taken in the late afternoon sun.
There's a new gallery viewer app "Calibrated Photo Viewer" with built-in color correction enabling photos to be seen in their natural colors. No rooting is required.
Adding a prefix "https://" to the following will take you to the app on Google Play
play.google.com/store/apps/details?id=com.auralisoft.jpegviewer
I thought I'd share this app since color correction/calibration is a genuine topic of interest to Nook HD+ owners and there doesn't seem to be any other app with the same functionality.
Cheers.