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A.net Compression. Definitely Needs Reviewing  
User currently offlineAer Lingus From Ireland, joined May 2000, 1543 posts, RR: 0
Posted (12 years 3 months 4 days 1 hour ago) and read 1595 times:

Woh, when I saw the large version of this shot I was completely taken aback at the loss in quality.


Click for large version
Click here for full size photo!

Photo © Martin O'Connell



The HUGE amount of compression visable in the sky and on the tail is unbelieveable. Honestly now if I viewed that shot in the large version and if it wasnt my own, I'd say to myself "how did that get in ?".
The strage thing is that when I uploaded it, it had NO compression whatsoeverand looked completely different.....

And no this aint some shameless plug......

Martin

30 replies: All unread, showing first 25:
 
User currently offlineJderden777 From United States of America, joined Jan 2000, 1754 posts, RR: 30
Reply 1, posted (12 years 3 months 4 days 1 hour ago) and read 1492 times:

Martin,
the shot looks absolutely fine to me....not compressed at all...it's perfect! i would definitely have added it to my database...i don't see any compression in the sky...and the tail...it looks good to me....

jonathan d.



"my soul is in the sky" - shakespeare
User currently offlineStaffan From , joined Dec 1969, posts, RR:
Reply 2, posted (12 years 3 months 4 days ago) and read 1474 times:

I had the same problem with one of my photos


Click for large version
Click here for full size photo!

Photo © Staffan Hardie



Here is the same photo before the compression.
Click here

Don't know what could be done about it though, if the photos were much larger it would increase the server loads too much.

Regards,

Staffan


User currently offlineCfalk From , joined Dec 1969, posts, RR:
Reply 3, posted (12 years 3 months 4 days ago) and read 1469 times:

I agree with Jon - I see nothing wrong.

Nice lighting.

Charles


User currently offlineAer Lingus From Ireland, joined May 2000, 1543 posts, RR: 0
Reply 4, posted (12 years 3 months 4 days ago) and read 1451 times:

Really ? ?

the way this is going people are going to think this IS a plugging session..........god........



User currently offlineLGW From , joined Dec 1969, posts, RR:
Reply 5, posted (12 years 3 months 4 days ago) and read 1447 times:

Martin, is this that post you where saying you where going to create to boost your average?

LGW

 Big thumbs up  Big thumbs up Big thumbs up


User currently offlineMcringring From , joined Dec 1969, posts, RR:
Reply 6, posted (12 years 3 months 4 days ago) and read 1435 times:

I can see some compression by the nose, the wing and the tail, but it doesn't look like that big of a deal. Of course when you upload something and it turns out looking different it's easy to get upset. Especially since the scripts are supposed to decrease the file size without any loss in quality.

User currently offlineH. Simpson From United States of America, joined Mar 2001, 949 posts, RR: 3
Reply 7, posted (12 years 3 months 3 days 23 hours ago) and read 1417 times:

may be your eyes are compressed??? Big grin

User currently offlineEDIpic From , joined Dec 1969, posts, RR:
Reply 8, posted (12 years 3 months 3 days 23 hours ago) and read 1408 times:

When I see some photo's on my screen looking crap, check your monitor.
It can change from 32bit back down to 16 bit.. or fewer colours?

Some other programmes can change a PC's monitor settings.
(Like my son's Championship Manager!)

Gerry/EDI


User currently offlineMudozvon From Russia, joined Nov 1999, 88 posts, RR: 1
Reply 9, posted (12 years 3 months 3 days 22 hours ago) and read 1395 times:

Very nice shot. The shadow from the wing is Something!!!
Nothing wrong to my eye here.
Leonid


User currently offlineStaffan From , joined Dec 1969, posts, RR:
Reply 10, posted (12 years 3 months 3 days 22 hours ago) and read 1388 times:

I nominate Gerry for the Nobel prize, changing the monitor to 32 bit actually helps...

Guess this thread can be archived or deleted now...

Staffan


User currently offlineEGGD From United Kingdom, joined Feb 2001, 12443 posts, RR: 36
Reply 11, posted (12 years 3 months 3 days 22 hours ago) and read 1384 times:

I see that compression, on both shots, maybe it is you guys who should get your monitors checked out! I typed out some crap before about why you see the compression so bad on these shots, but I guess its not really that important.

Regards

Dan  Acting devilish



User currently offlineStaffan From , joined Dec 1969, posts, RR:
Reply 12, posted (12 years 3 months 3 days 22 hours ago) and read 1380 times:

I also noticed a funny thing, if I open an a.net photo while in 16 bit, then switch the monitor to 32 bit and open the same photo in a new window, they don't look the same compared side by side...  Confused

Thanks alot, now I'll enjoy this alot more!!  Smile/happy/getting dizzy



User currently offlineEGGD From United Kingdom, joined Feb 2001, 12443 posts, RR: 36
Reply 13, posted (12 years 3 months 3 days 22 hours ago) and read 1372 times:

cooooooool, now i've changed it to 32bit it looks twice as bad!!!

User currently offlineStaffan From , joined Dec 1969, posts, RR:
Reply 14, posted (12 years 3 months 3 days 22 hours ago) and read 1369 times:

Reload and it won't!



User currently offlineEDIpic From , joined Dec 1969, posts, RR:
Reply 15, posted (12 years 3 months 3 days 21 hours ago) and read 1357 times:

I was just about to flame you Staffan!
.... Thanks for the apology!



User currently offlineStaffan From , joined Dec 1969, posts, RR:
Reply 16, posted (12 years 3 months 3 days 21 hours ago) and read 1350 times:

I'm confused...did I say something wrong? It wasn't aimed as a rude message.

Sorry if you missunderstood me.

Regards,

Staffan  Smile


User currently offlineEDIpic From , joined Dec 1969, posts, RR:
Reply 17, posted (12 years 3 months 3 days 21 hours ago) and read 1348 times:

You mean it really helped?
The English language is such an ambiguous communication device!

Glad to be of service!

And what about Martin... resolved?

Gerry/EDI


User currently offlineStaffan From , joined Dec 1969, posts, RR:
Reply 18, posted (12 years 3 months 3 days 21 hours ago) and read 1346 times:

Yeah, it looks perfect now! Thanks!

Staffan  Smile/happy/getting dizzy


User currently offlineTomH From United States of America, joined May 1999, 960 posts, RR: 2
Reply 19, posted (12 years 3 months 3 days 20 hours ago) and read 1335 times:

Martin,
Well, you got me to open the thing up twice, so I suppose that helps the hit counter. I don't understand how you feel you can judge the amount of compression by looking at sky, rather than detail on the aircraft itself.

More importantly, what was the file size you uploaded compared to the large version on A.net? That ratio should tell you something significant about the actual amount of compression. I noticed also that your H was <1024. I thought we were trying to standardize on 1024 at Johan's suggestion about 6-8 months ago. Yes, I know, it's optional, but I'm curious to know why so many folks aren't following the recommendation.


User currently offlineCkw From UK - England, joined Aug 2010, 713 posts, RR: 16
Reply 20, posted (12 years 3 months 3 days 19 hours ago) and read 1315 times:

Tom, for info, compression is more detectable in the sky (or any areas of similar tone) than the aircraft because .jpeg works by compressing areas of similarity by throwing away "unnecessary" pixels. This can become apparent as a "blocky" appearance on what should be smooth tones (because some of the transitional colours have been dumped).

In areas where there are significant contrast variations (eg. on the plane itself) the compression program assumes this means interesting detail, so throws away less.

Another thought on this - don't some dial-up "speed-up" programs apply compression on the fly? Is it possible some ISP's might do this?

Cheers,

Colin



Colin K. Work, Pixstel
User currently offlineDa fwog From United Kingdom, joined Aug 1999, 867 posts, RR: 8
Reply 21, posted (12 years 3 months 3 days 14 hours ago) and read 1302 times:

Colin, how would this work?!!? You have to get the data before you can compress it, by which time it's already reached your PC. You could only compress OUTGOING data! As for ISPs doing it - the processing overhead to re-compress a jpg would be prohibitive. Any idea how many there are in the average web page?  Nuts

Agree with your comment about the sky though. And the reason this is more detectable if you don't have your graphics card set to enough colours is that the exact colour chosen by the compression algorithm may not be available, so your graphics card will choose the next nearest one. This just compounds the "blocky" effect of the compression and makes it look even worse!


User currently offlineCkw From UK - England, joined Aug 2010, 713 posts, RR: 16
Reply 22, posted (12 years 3 months 3 days 11 hours ago) and read 1285 times:

Chris - you're right of course - it was late, I'd just spent hours fixing my PC, I was so releived just to be able to get it online again that I wrote any old rubbish - I was thinking of on-the-fly compression on the server side.

Cheers,

Colin



Colin K. Work, Pixstel
User currently offlineTomH From United States of America, joined May 1999, 960 posts, RR: 2
Reply 23, posted (12 years 3 months 3 days 8 hours ago) and read 1279 times:

Colin,
I understand what you are saying about the sky. I think GIF files work in a similar manner, compressing more the white background of a document and less the printed area. Still, when someone says they can see it in the sky, are they looking at the image 100% or (more likely) some greater magnification? I didn't notice anything in the sky at 100%, but I haven't taken a second look.

I have heard AOL.com compresses all images unless you contact them and request they desist. I would assume this is on xmit side of their server of course.
Tom


User currently offlineCkw From UK - England, joined Aug 2010, 713 posts, RR: 16
Reply 24, posted (12 years 3 months 3 days 7 hours ago) and read 1274 times:

Tom - I can't see any compression either - I think it was a case of people viewing in with a 16 bit display setting - can look similar. Gif files work slightly differently in that they use a very limited palatte for images - which is why its a poor format for photos.

Cheers,

Colin



Colin K. Work, Pixstel
25 Aer Lingus : Thank you all for the inputs and please please please understand that this was not any gimmic to get extra views. It was something that I felt looked
26 TomH : Martin, It was a while back that the image deminsion size of 1024 was brought up. I increased my average width to agree with what I took to be a new s
27 Da fwog : A.N. DOES compress the jpgs you upload. This is pretty sensible when you think about it. Some people optimize their jpgs before uploading (to get maxi
28 TomH : Is the compression automatic? Hard to imagine they would do it manually. They can't tell how much compression I have already applied, right? So how ar
29 Ckw : Tom - I think that's why they recommend upload with 0 compression, as the subsequent compression has a cumulative effect. Cheers, Colin
30 TomH : You are probably right on reason for the 0 compression request. To be truthful, I laughed when I first read that 0 compression advice way back. To me,
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