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JPEG Compression

Sander K 

Member
Joined in March 2015
Posts: 3
Posted 9 November 2015 - 23:02 CET

hey,

im having troubles with this picture that i tried to upload multiple times, but its getting rejected due to JPEG Compression, i tried different thing such as adding some blur or noise, but it didn't work so well. Does somebody know a different way to remove JPEG Compression? Thanks in advanced!

Sander.

Attached photos:

Murmeldeier 

Full member
Joined in August 2008
Posts: 151
Posted 10 November 2015 - 06:47 CET

I think (but I can of course be wrong) that the main issue in this picture is the sky which shows indeed some "compression" or "artifacts" or "banding".

This is perhaps the result of to much noise reduction.

Try perhaps to rework the picture from the begining (I mean before applying the noise reduction) and reduce the amount of noise reduction, especially on the sky.

Ricardo Hebmüller 

Full member
Joined in August 2014
Posts: 89
Posted 10 November 2015 - 09:56 CET

I am far below from being a screener or a full member, but I will risk to tell you my opinion. It is a beautiful picture but we can see some banding in the sky. I would select the aircraft and the bottom part of the photo and apply all my features or workflow only to that part. I would let the sky with the minimum treatment possible.

Oliver Louis

Full member
Joined in January 2015
Posts: 47
Posted 10 November 2015 - 15:17 CET

Hi Sander,

there are visible bandings in the sky (they can also appear after some sort of editing, not alone by de-noising). The second point is (my opinion), the aircraft is a bit over-sharpened.

Regards,

Oliver

Sander K 

Member
Joined in March 2015
Posts: 3
Posted 10 November 2015 - 16:28 CET

thanks for the feedback all!

@Oliver, i've seen that too, this was also a test for a new workflow for me, wont be using it now.

Sander.

Sebastián Ulloa 

Member
Joined in April 2015
Posts: 25
Posted 10 November 2015 - 16:33 CET

Hey Guys,

Will take the chance same as Ricardo, as he mentioned far from being a screener, I would take the editing from scratch.

Not sure if my recipe will work, but wouldn't hurt to take a chance.

I would take it to Lightroom, do the lens and chromatic aberration correction of the lens and check for any unwanted dots in the pic, will later take it to Photoshop, would align it and crop it.

Then would do the exposure and color balance, them de-noise and would work on the pre-sharpening, adding some control points over the sky (where the problem is right now), will later do a little bit of tonal contrast over the sky with color efx and a little of detail extractor, not to much tho.

Last but not least, resize, check for the out put sharpening just at about 15% opacity and them export.

May help a bit, it helped me, I saw most of it in a Andre Nordheim tutorial.

Cheers

Sebastian

Helen Brown
Member
Joined in February 2016
Posts: 1
Posted 17 February 2016 - 02:47 CET

hi i had that same problem and its ur photo is being push together. i could solve it when i saved it it came up with two pictures one was the normal one and the other showed me what it was gonna look like after i moved the slider at the bottom and that seemed to of worked

AlphaMike 
Full member
Joined in December 2015
Posts: 23
Posted 18 February 2016 - 13:48 CET

That's not jpeg compression (which is invariably more blocky) - as has been mentioned above, it is colour banding you can see in the sky.

Banding sometimes occurs when very subtle changes in colour occur across an image. Simplistically, a jpeg image has 8 bits per channel - that's 256 tones of red (from almost white to very deep red), 256 tones of blue and 256 green. When an image is recorded, for each pixel the closest tone to the actual light, selected from from those 256 tonal values, are used.

Occasionally, a subtle colour change across an image means means one pixel gets one of the 256 red (and blue and green) tones, while the pixel next to it gets recorded at a different level. Most times this isn't a problem because colour changes tend to take place on hard borders - cheatlines, fuselage to sky boundaries, etc. or the change in colour is large anyway, in which case being slightly out won't notice. But sometimes, the really subtle colour changes in a sky can result in adjacent pixels recording at different levels of R, G and B. The changes are so slight that the eye doesn't notice (and they eye can recognise more colour levels anyway), but they sets up a hard boundary on a digital image that didn't exist in reality. And those edges are the banding you see in the image.

It can be worse when a picture is already over saturated, and can be exacerbated if you try to push the curves in post-processing to deepen or lighten large and fairly uniform looking dark areas - as you might be tempted to do to darken that already moody sky.

How to fix it? Shoot RAW, work with 16-bit images (65,532 levels of R, G and B instead of 256) and only go to jpeg (8-bit) at the last second. If you're already stuck with an image that exhibits branding, common consensus seems to be the easiest method is to introduce a bit of noise (which it seems you've tried and hasn't worked). There are other ideas floating around online.

Matt Reynolds 

Full member
Joined in December 2015
Posts: 30
Posted 18 February 2016 - 15:47 CET

Saving using the "Bi-Cubic Smoother" option as advised to myself by Angelo can help as well!

Sander K 

Member
Joined in March 2015
Posts: 3
Posted 18 February 2016 - 18:36 CET

Hi all,

i have solved this problem by only selecting the plane, this is the result:

http://www.airplane-pictures.net/photo/635253/ph-mcw-martinair-cargo-mcdonnell-douglas-md-11f/

thanks for all the tips!

greets Sander :)

Nigel Paine 
Full member
Joined in November 2008
Posts: 54
Posted 18 February 2016 - 19:20 CET

Nice work, Sander. Looks good :0)

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