Benchmark of image hosting services and improvement suggestionsPosted: August 15, 2011
One of my hobbies is photography and I often find myself sharing pictures on web forums about photography. Very often, these forums do not allow to directly upload your pictures on their servers, in order to limit bandwidth. Then, I need an image hosting service to do that. There are many of them. I did a quick comparison of 4 of them, from the perspective of a photography enthusiast, who’s looking for a convenient and quick way to share photos on the web, while preserving image quality. The four contestants are the FREE versions of:
I stuck to the free versions because if one is allowed to pay, another possible solutions is to get some private web space and host the pictures there. On top of that, while in the description of each provider, I also mention the uploaders, in the “results table” I limited my considerations to the web-based versions (rather than the uploaders), because there are several non-official uploaders and reviewing them all would have taken too long. If you want to contribute by adding information, you are most welcome to comment and I’ll be happy to integrate!
Besides commenting on usability and deep-linking policies (fundamental for sharing on forums), I uploaded 3 pictures on each of them to check the image quality. The three pictures are actually the same photo in 3 different sizes: LARGE, straight from my 12 MP camera (4288 x 2848) , MEDIUM, resized to 1072 x 712 (25% of the original size) and SMALL, resized to 536 x 356. I chose a picture that was not very detailed, with large blurred and dark areas to see how compression treated them. Here are the results.
Summary table (of purely web-based use – uploaders are not considered)
Flickr goes well beyond image hosting. It is the largest on-line community about photography, which gives visibility to your photos and lets you browse the photos of other enthusiasts. In terms of image quality, Flickr is OK, not great, not too bad. All images larger than 1024 pixels are resized. File compression is really really strange. While on the LARGE Flickr produced a smaller file thanks to the massive decrease in resolution, on the medium, which was still slightly resized to fit the 1024 limit, the file size INCREASED. This seems pretty strange, but I checked it multiple times. This might mean that the file is re-encoded, that is not great news, and will slow down the forum page more than necessary.
The MEDIUM image is slightly sharper than the LARGE one (it does not necessarily mean that it’s better, it could have been resized with different sharpness settings)
Flickr records the EXIF data in the web page corresponding to the image, but deletes them from image file itself, which is a big big minus, as it annoys the people who would like to comment on your photo on web forums
Getting link codes is relatively easy and you can even get the BBcode to share photos on the forum. However, it must be done one photo at a time.
Imageshack is much more about image hosting than about photo community. You can even upload photos without being registered. On the positive side, they do leave the files untouched, no resizing and no compression. Unofrtunately, though, getting link codes is not exactly easy. The BBcode and html links that are automatically generated for batch of photos will only allow you to embed a thumbnail in your forum post, linking back to the Imageshack page. If you want to embed the full size picture, you need to click on each page, look for the “direct link” and then type the BBcode tags yourself.
Or… you can use the uploader! With the Imageshack uploader, you get the BBcode ready for the whole batch, straight from your application. Kind of cool!
Imageshack also preserves the EXIF data.
Links: not available (impossible to get the code)
While Picasa is intended more as a community than as an image-hosting service, it is a lot more similar to Imageshack than to Flickr (at least from the angle of someone who wants to post on web forums). Just like Imageshack, Picasa does not resize or compress photos and does not make it easy to get the BB code of the full size image. Html code (but not BBcode) is provided for embedding a resized version of a photo in a webpage (800 pixels), but I could not figure out how to get the URL of the full size image. The direct link is an https, which only works if one is logged in as the one who posted the photo. Then, sharing the full size photo is actually impossible.
Picasa preserves EXIF data, but only on the full size download (not on the preview images embedded in Picasa pages)
If I had to choose my hosting service purely based on convenience, it would be Photobucket. Uploading is quick, the html links and BBcode for the FULL size images are generated with just one click for the whole batch of image I have just uploaded and the EXIF data are fully preserved.
The only (massive) issue is compression. Besides resizing images larger than 1024 pixels, Photobucket aggressively compresses them, to the point that jpeg artifacts and noise are often disturbing. For a photo enthusiast who has spent hours on processing his photos and hundreds (or thousands) of euros for a sharper lens, this is unacceptable.
Looking at the photos, the LARGE one is slightly sharper than the MEDIUM one. This is the opposite of Flickr, but the same considerations about sharpness settings apply.
Conclusion and suggestions to providers
My current provider is Flickr. It has neither the convenience of Photobucket, nor the quality of Imageshack, but it is a good compromise. After doing this benchmark, I’m considering switching to Imageshack (I was not aware of the full-size BBcode in the uploader until now). I need to think whether it is worth leaving the Flickr community for the advantages of Imageshack uploader.
And the suggestions now: if I was Flickr, I would definitely leave the EXIF data on the photo file. If it’s a matter of privacy, just remove location and date, but leave camera make and model, exposure time, aperture, ISO sensitivity, etc… And I would investigate on the (de)compression algorithms.
If I was Photobucket, I would not be so aggressive in compression. Is a 30% reduction of storage and bandwidth costs really worth pissing off photographers? Resizing larger images is OK (most forums have a 1000 pixel limit anyway), but why compress small images so much? On the opposite side, for Imageshack: why not show BBcode for batches of full-size images on the web-based version as well? (not everyone uses the uploader all the time)
You are obviously welcome to comment on this!