Photo hosting websites

[Herodotus]

Do photos hosted on different hosting websites look different?

EDIT: Photos removed

[Keith]

Pretty close if not the same. If anything the Flickr pic strikes me as having just a tiny bit more color if you examine the stem and leaves, but that could just be a trick of the eye.

[Herodotus]

Thanks Keith.

Actually that's more or less what I thought.

It seems to me that one has lost some colour and contrast compared with the other two. But the other two are very similar, but I also think the Flickr one seems better.

What I don't fully understand is how this can be, because it is the same file stored in three different places. The only thing I can think is if they are reduced and compressed in different ways when they are uploaded.

The pictures will disappear in a few days

[Keith]

Yes, it's probably the differences in the way they are being processed on the host site. The differences are very slight though.

If you re-download the image from each site do they retain the difference or do they look like the original you uploaded?

[Herodotus]

That's a good question.
Actually they can be downloaded simply by right clicking which it is why it is so easy to steal images.
If I download and look at them side by side in Photoshop elements, I could easily pick out the Flickr one as the best without knowing for sure which was which.

But they were definitely compressed differently:
The images are all 640 x 640 pixels and File sizes after redownloading were:
Left 97 kb
Middle 102Kb
Right 174 Kb

The really strange thing is the original file I uploaded which was 740 x 740 was 79Kb, so maybe the upload mechanism also includes simple automatic post processing like levels, contrast, unsharp mask etc

So seems like no contest unless there's a way of specifying quality when you upload... Dunno.

Thanks for being a sport Keith.