View Full Version : Which is the best quality image?

July 16th, 2008, 01:35 PM
Hi All,

The following post is related to some University work I have been doing. Since the Ubuntu forums have always proved to be very useful with my linux questions, I thought I would try to pick the brains of some of the forum users for something a little different.

After some image restoration work for my computing degree, I have now come to the point where I need to measure the quality of some restored images. Part of this analysis has involved using different metrics such as VIF, MSSIM, PSNR HVSM and PSNR to measure the quality of the restored images.

Now I would also like to conduct a subjective analysis, which is where YOU can help! :)

I have uploaded a single image containing different results, and I would be extremely grateful if you would be able to take 30 seconds out of your time to rate the images in order of visual quality. The link to the images is
(please don't forget to use the zoom option on your browser if it automatically shrinks images to fit... the closer you can see the images, the more accurate your analysis will be).

Each image is numbered (from 1-5). What I would like is for you to reply to this thread with your opinion on the order of the images, from best to worst (where image 1 is the best quality, and image 5 is the worst).

For example, if I thought the best image was number 2, and the worst was number 1, I would post something like the following:


and also a quick explanation as to why you thought some were better than others (if you have time!...the results are much more important than an explanation).

Many thanks in advance,


EDIT: Please note that just the nose region differs in each image, so that should be where you direct your eyes ;)

July 16th, 2008, 01:43 PM

Edit: Showing us what the image was originally would have helped very much.

July 16th, 2008, 01:45 PM
It's a tough call, but I'd say: 3, 2, 5, 4, 1

3 and 2 seem more detailed (less blurring) than 5 and 4, and pixelation (in 1) is never nice looking.

P.S. For some reason I always get a chuckle when I see that image used for testing purposes ;) (It's "Lena" isn't it?)

July 16th, 2008, 01:46 PM
ok here goes -


so simply due to the sharpness of the nose - (by the way - you may want to make it more clear that it is just the nose area that is differant quality)

so 2 is sharpest by a long way - most contrast and range of shading
then 3 as it become much more blurry
5 and 5 close, but 5 is brighter
then 1 since it is so pixelated.

hope i helped

July 16th, 2008, 01:46 PM
2, 3, 5, 4, 1

2 and 3 look similar, and look the best because they have some grain while keeping some detail.
4 and 5 look similar, but just look blurred, which does not suit the image's grainy look.
1 just looks awful, too pixelated.

July 16th, 2008, 01:52 PM
@everyone: thanks for the replies so far! Much appreciated :)

@jomiolto: sure is Lena! It's kinda become a standard image processing image since it has a good variation of high and low frequency, and colours (when not in greyscale!)...plus also helps that the image was ripped from a playboy magazine ;)

@phantomjoker: thanks for the suggestion...I've updated the post

July 16th, 2008, 01:56 PM

July 16th, 2008, 02:09 PM
2, 3, 5, 4, 1

July 16th, 2008, 02:10 PM

With the exception of the badly pixellated nose job in #1 they're all the same to me.

July 16th, 2008, 02:14 PM
Well, I'm a bit old with old eyes, and to me 2,3 are the same, and 4,5 are the same. 1 is worse though. So:


Sorry to be awkward. :)

July 16th, 2008, 02:14 PM
2 3 5 4 1
one is very pixelly :]
4 5 are a bit blurry. two is the best

July 16th, 2008, 02:15 PM

July 16th, 2008, 02:16 PM
this is my opinion 3, 2, 4, 5 1

for me 1 is too pixelated.

July 16th, 2008, 02:17 PM

July 16th, 2008, 02:26 PM

July 16th, 2008, 02:47 PM

July 16th, 2008, 03:08 PM

I must be weird or some thing since no one has seen close to what I see.

July 16th, 2008, 03:13 PM

July 16th, 2008, 03:17 PM

I must be weird or some thing since no one has seen close to what I see.

Nah, if you was weird number 1 would be the best quality. :)

July 16th, 2008, 03:21 PM
After studying them I reckon:

3, 2, 5, 4, 1

Except for 1, the only difference appears to be blurriness. For 1, you seem to have some mighty large pixels! ;)

July 16th, 2008, 03:24 PM
Me thinks: 3, 2, 5, 4, 1

3 and 2 are very close, 5 and 4 are very close, and I think 1 is supposed to be the 'original' distorted image, so it is obviously the worst :)

July 16th, 2008, 03:24 PM

July 16th, 2008, 03:32 PM
2 3 5 4 1

July 16th, 2008, 04:08 PM
3,2,4,5,1 As an old film photographer 3 appears to be a fine grain and sharper. 2 looks like a larger clumpier grain and less sharp. 4 5 & 1 I would trash the negatives.:)

July 16th, 2008, 04:42 PM
3, 2, 4, 5, 1 here

July 16th, 2008, 05:16 PM

I rated number 1 last because of the blocking (not sure of correct term) in the nose area. I found 2 and 3 best because they had the least blurring in the nose and right cheek area. Images 2 and 3 appeared similar, as did images 4 and 5