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Limitations of JPEG format prevents me to upload images with noise-free sky

Robert Kaffan 
Member
Joined in June 2016
Posts: 10
Posted 14 October 2017 - 23:36 CET

Hello,

I have a problem I can not solve. It is called "digital noise" some censors use to reject a photo, while not understanding that it is the JPEG format which creates this noise because of its limitations.

Please have a look at this picture library.

https://photos.app.goo.gl/ll26nkZjHvhzzTIz1

Description of photos:

(1) A photo uploaded to AP.NET and rejected by censor Toshihiko Takamizawa (14.10.2017, 16:55:11 CET, Digital noise is visible. Simple noise mitigation works fine.)

(2) Equalized version of the rejected photo - you can see some noise in the sky. It is barely visible on the actual picture, but it is there. Still, I think that rejecting this photo on grounds of sky noise was unjustified. But that is my personal opinion.

(3) The same picture, newly developed, noise removed in Dfine 2 and saved in 16-bit PNG format. Please notice zero noise in the sky. This is the picture I have on my computer and this is the quality I wish to display and upload to AP.NET.

(4) Equalized picture of this newly developed photo - still 16-bit PNG format. It confirms that the sky is very smooth. There is virtually no noise in it.

(5) This is an 8-bit JPEG picture created by converting 16-bit PNG picture (3) into JPEG format, 4:4:4 subsampling, floating point DTC conversion, 100% quality. It is the best JPEG you can get. There is just no higher JPEG setting available.

(6) Equalized version of picture (5). THIS IS MY POINT HERE. Please compare picture (4) to picture (6) and see HOW MUCH NOISE WAS INTRODUCED by JPEG format! You can see all kind of noise in the sky on picture (6), which is simply not there on picture (4)! This noise is JPEG noise, it is created when converting a 16-bit image into to 8-bit image where image information is LOST and can not be reconstructed despite highest JPEG settings.

So imagine my frustration. I have a noise free 16-bit image on my computer. But I can not upload this 16-bit quality to AP.NET, because only JPEG pictures are accepted. And then Toshihiko Takamizawa comes and tells me there is noise in the sky. Of course there is, JPEG format caused it. And I can not do anything about it, which frustrates me.

(7) Picture (5) uploaded to AP.NET, watermark added. This picture now sits in the queue waiting for screening. The digital noise was removed in Dfine 2, as suggested by Toshihiko.

(8) Equalized version of picture (7). Again, please compare picture (8) to picture (4) and see the difference in the sky noise. This noise is not mine. This noise is JPEG noise at 100% quality setting. Picture (4) confirms it.

If this uploaded picture gets once again rejected on grounds of digital noise, then I simply don't know what I will do. Because I will be having pictures rejected on grounds of noise that is INHERENT to JPEG format and which can not be avoided.

Please help me. Can you convert picture (3), which is a noise free 16-bit version, into JPEG format without getting noise in the sky? I can not. Despite 4:4:4 subsampling at 100% quality setting and DTC set to floating point (which is supposed to provide higher quality than integer setting).

Ramon Jordi 

Member
Joined in November 2010
Posts: 17
Posted 15 October 2017 - 17:42 CET

+1

Hi Robert,

I have the same problem and I have spent a lot of time investigating. Dfine2 sometimes, not always, generate noise in the sky. I am not able to know the reason.

What I'm doing is not editing the sky, just the plane. Sometimes it works and sometimes it does not.

Regards and patience. :-)

Ramon Jordi 

Member
Joined in November 2010
Posts: 17
Posted 15 October 2017 - 18:11 CET

Sorry, I wanted to say that sometimes Dfine2 generates JPG compression problems, not noise.

Boytronic 

Full member
Joined in March 2015
Posts: 80
Posted 15 October 2017 - 18:32 CET

Hi Robert,

Don't worry, there are tricks how to solve this issue but also keep in mind that some of the screeners are too strict about some stuff while some pics that show lack of quality seen with a naked eye get published....unfair? - yes, some hide their "quality" behind 1200px - yes.....this topic goes on and on forever but nobody can't change it so don't bother yourself with it.

I'll tell you that is not all about JPEG compression and monitor size, whatsoever...some things you lose by default when you convert and compress but that's only visible in equalize mode. What you see on a good monitor is pretty much what you get in prints if the printing lab is ok. I've been doing some designs and have lot of friends and colleagues who are pro designers and none of them use equalize mode for nothing although they all are PS wizards...so if you're pic is rejected it DOESN'T MEAN it is not low-grade or bad quality!

But there are a couple things that can cause that problem even more visible when compressed to jpeg;

1) lens quality (in my experience some lower quality glass can do a horrible noise even in a raw) especially when you have that blue/gray shitty sky as in this particular photo.

2) try to eliminate noise in Lr (if you use it and know how) even before Dfine2 applied! a very simple trick....(if you need my advice how I do it and have no digital noise problem in 99%, please contact me...

About 4K myth; what will you do that 4K resolution monitor is needed and better yet, will it be noticeable? It is a great plus to have it of course but not essential. What ever you do it still mostly ends up in full HD resolution and it is still a standard. You must understand printing technique and process to have it justified.

A short video comparison; 4K, 5K...8K in video? Yes! Wanna know why? (believe me, you don't see 4K on Youtube no matter how good monitor you have!) It's simply because they need much more raw information for CGI details and all coloring post production manipulation as well as frame positioning and zoom in...the same is with photos so if you know your stuff you can have perfect photo with 1920px, just if it's sharp enough and edited without any technical mistakes. Myth solved.

Best regards,

Boytronic

Igor Kmet 

Full member
Joined in September 2013
Posts: 91
Posted 16 October 2017 - 09:48 CET

Hi Robert ,

i made standart transformartion from your png format picture (3) to jpg in PS, save for web..

Maximum, 100 , Bicubic and there is no digital noise in the sky ..

Attached photos:

Igor Kmet 

Full member
Joined in September 2013
Posts: 91
Posted 16 October 2017 - 09:48 CET

..and equalized

Attached photos:

Robert Kaffan 
Member
Joined in June 2016
Posts: 10
Posted 16 October 2017 - 11:39 CET

Here is my equalized version of your shot, Igor. There is a standard JPEG noise visible in the sky. JPEG can not render smooth color transitions.

The noise is JPG noise. If this picture gets rejected on grounds of sky noise or digital noise, it will mean that AP.NET rejects images that are caused by JPEG format and can not be avoided.

Attached photos:

Kuba Balcerski 
Member
Joined in January 2016
Posts: 33
Posted 16 October 2017 - 17:20 CET

Do you even realize that every member of this site is uploading the photos in JPG format (because it's the only possible format, by the way) so that's not really the problem with the file format since thousands of photos were already accepted through the years?

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