ikeharel - Pre-screen / Pre-upload advice

[dlowwa]

Hi Dana,
Thanks for the advise.
Anyway, the general question is about the guidlines which I expect a clarification, as I see many photos where the planes is not centered in an "airport overview". can you refer to this issue?
Also, why in the first rejection I got, there was other remark ("Horizon unlevel"), which I fixed and re-upload, but had no reference to the "bad composition..." issue?
Sincereley,
Ike

Can't really comment on the latter having not screened either of the images in question. As for guidelines, there is nothing specific, I'm guessing the image above was rejected simply for aesthetic reasons (with which I'd tend to agree). Sorry if that doesn't help too much!

[ikeharel]

Can't really comment on the latter having not screened either of the images in question. As for guidelines, there is nothing specific, I'm guessing the image above was rejected simply for aesthetic reasons (with which I'd tend to agree). Sorry if that doesn't help too much!

Thanks for the reply, Dana.
Indeed, aesthetic reason, which always in the eyes of the beholder, and there is nothing in the guidlines about it - that's exactly my point.

As mentioned - saw several accepted photos to JP gallery where the plane / or planes were not centered in the overview image.

Luckily, this airfield is about 16km from home, so I will be able and intend to visit the place yet again.
Good evening,
Ike

[ikeharel]

This was first posted on the "Aviation photography forum" section on July 22nd and never got an anser, so here is a re-post, with hope to get an answer:

Hello to the screening team,
I had recieved an E-mail with an appeal rejection for this picture of a Delta plane reg. N407DX.
The answer was as follows, quote: " Your appeal for photo id 9286366 has been processed and has been rejected.
Admin Comments : Sky shows signs of breaking up and colour blocking. "

The original rejection was "JPEG compression artefats" . Than, stated in my appeal that:
1. No compression is shown on the main photo.
2. The so-called artefacts on the Equalizer picture are merely a light-heat differential's ( which happend at high summer hot days ) and notable that the "artefacts" not shown over the entire picture, i.e. the lower part differ from the upper part as a result of what I explained about light heat differential above.

My question is, as I never got an explanation like "Sky shows signs of breaking up and colour blocking. "... what this answer stands for?
Can anyone re-assess my appeal, as in my humble opinion the picture is fair to be accepted.
Sincereley,
Ike Harel





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[Ben Long]

Firstly, I am not a screener.

If you pay careful attention to the sky, you can see various shades of blue in block-like shapes. It almost looks like a wall of lego built out of similar shades of blue. This is what the screeners mean by "colour blocking". You can see it a lot clearer when we strip away the colour itself:

As you can see, there are blocks of contrasting tones/shades indicating image compression. This is not a natural occurrence. However, you're right that things such as heat and, particularly, smoke (as I experienced during our 2019 bushfires here in Australia) can create artefacts in the sky as seen on equalised images. These look different to compression, though.

I would wait for an experienced screener to have their two cents, though.
Regardless of the outcome you cannot appeal an appeal, both the photo and the appeal have been rejected.

Regards,
Ben.

[ikeharel]

Firstly, I am not a screener.

If you pay careful attention to the sky, you can see various shades of blue in block-like shapes. It almost looks like a wall of lego built out of similar shades of blue. This is what the screeners mean by "colour blocking". You can see it a lot clearer when we strip away the colour itself:

As you can see, there are blocks of contrasting tones/shades indicating image compression. This is not a natural occurrence. However, you're right that things such as heat and, particularly, smoke (as I experienced during our 2019 bushfires here in Australia) can create artefacts in the sky as seen on equalised images. These look different to compression, though.

I would wait for an experienced screener to have their two cents, though.
Regardless of the outcome you cannot appeal an appeal, both the photo and the appeal have been rejected.

Regards,
Ben.

Thanks, Ben.
I gave up about getting an answer - apparently nobody wants to deal with a problematic subject as JPEG-Compression.

This is not JPEG-Compression case, the upper part differ pattern from lower part (On a "real" compression case the entire picture-space should look with same pattern i/e/ the small "block-like" cubes). Thus, this picture specifically has merely hot sky with strong summer-light-heat, which measured by Kelvin numbers greater than 8000.
In any case, it is not visible on the original / main picture uploaded.


Thanks again,
Ike

[B7772ADL]

Ben pretty much summed it up and doesn't really need any further clarification.

Looking at the colour image you attached in this thread I can clearly see blocks of colour through the sky. They are square, not rounded, so the photo has been assessed as having signs of compression. The photo will not be accepted when the sky looks like this. Maybe you should re-visit the original and re-process it. Maybe use masking so that the sky is untouched whilst you deal with the processing on the aircraft itself.

[ikeharel]

Ben pretty much summed it up and doesn't really need any further clarification.

Looking at the colour image you attached in this thread I can clearly see blocks of colour through the sky. They are square, not rounded, so the photo has been assessed as having signs of compression. The photo will not be accepted when the sky looks like this. Maybe you should re-visit the original and re-process it. Maybe use masking so that the sky is untouched whilst you deal with the processing on the aircraft itself.

Thanks James,
As I wondered, #1 : why was I waiting 27 days to get any answer?

Secondly, it is a long-time standing debate about compression, and I am not argueing about - but the original RAW was about 5800 pixles > converted when it was cropped to about 3900pixles, sized down to 1600 pixles, so not much of a compression as usual when I process planes pictures (I do not use any Photoshop - only Canon-DPP software).

Third thing In my mind: in the past I raised this isuue and stated that if the compressin doe's nots shown on the main picture, only on the equalized photo - than it should be accepted, and indeed some of my argued appeal were accepted. So differnt time's - different result.

I can live with it, the site is more valuable than just a debate about accepting pictures.
Sincerely,
Ike

[Alex - Spot-This !]

Ike, point is that those squares are very visible on the non-equalized version, on both my screens. Those squares are compression, either from editing or during saving process. They were also seen by the 2 screeners + the senior who screened your photo and by Ben here. So if you can't see them maybe you should consider a screen calibration ?

As a reminder we do NOT screen the equalize version, we only use it to confirm a 1st impression, most of the time on haloes and dust. I wouldn't have used it on such a clear case as compression here.

Hope it helps
Alex

[ikeharel]

Ike, point is that those squares are very visible on the non-equalized version, on both my screens. Those squares are compression, either from editing or during saving process. They were also seen by the 2 screeners + the senior who screened your photo and by Ben here. So if you can't see them maybe you should consider a screen calibration ?

As a reminder we do NOT screen the equalize version, we only use it to confirm a 1st impression, most of the time on haloes and dust. I wouldn't have used it on such a clear case as compression here.

Hope it helps
Alex

It helps, Alex, appreciate the answer.
Just will add something to this: at same time maybe 15 minutes interval from the Delta plane landing, I took one more a/p picture that was accepted, same size of wide body - and my process was the same, rutine with Canon DPP. Just saying, light was the issue here - not the PP.
Good evening,
Ike

[B7772ADL]

I still can't believe that you can't accept our opinion that it is compression. The blocks visible are square. This is digital. How does your "lighting issue" create digitally square perfect pixels? Would love to see your links on the web to prove your theory. Maybe we are wrong, so this is your time to prove it to us.

[ikeharel]

I still can't believe that you can't accept our opinion that it is compression. The blocks visible are square. This is digital. How does your "lighting issue" create digitally square perfect pixels? Would love to see your links on the web to prove your theory. Maybe we are wrong, so this is your time to prove it to us.

Dear James,
It is a repeating issue I encounter every summer. In Israel costal planes summer is hot and humid - rarly I see this phenomenon on other seasons. Most of my rejections on summers, years back, were upon this issue.
I once consulted an acquaintance of mine, he is a scienitst an expert on photonic's and he explained this for me, in length with great patiance on three diff. conversations.
Not everything I can and know how to find on the web. but I will try.
Thanks for your time,
Ike Harel

[ikeharel]

To James:

This is the best I could find at this momernt.
Ike

[ikeharel]

Another article about JPEG-Compression found on the web.

the second paragraph states that luminance can effect compression:
Ike

[ikeharel]

I still can't believe that you can't accept our opinion that it is compression. The blocks visible are square. This is digital. How does your "lighting issue" create digitally square perfect pixels? Would love to see your links on the web to prove your theory. Maybe we are wrong, so this is your time to prove it to us.

One final word from my side on this issue - with hope not to "employ" the screening team about any more, James:

As written before, a "perfect" compression should be eqally spreading over the entire picture space, not only 2/3 of the picture.
There is a considerable difference from the upper part to lower part of the picture - that's why I stated it's a heat of light differentials.
Sincerely,
Ike Harel

[B7772ADL]

So, at the end of the day, it's still compression