Flickr vs Picasa – A Quality Comparison
13 January, 2008 7 Comments
Last year I took a look at Flickr and Picasa (see Photo faceoff: Flickr vs. Picasa) with a view to determine which service was better suited to my future needs for online photo storage and sharing. At the time I concluded Picasa was better than Flickr’s free offering.
Yesterday, a visitor posted a comment on that original entry suggesting that Flickr displays higher quality photos. Initially I was skeptical and thought it might have been something to do with the way the photos were uploaded, or dimension constraints, so decided to check it out myself.
My conclusion? There is NO difference in quality between the two – but there are caveats with that statement.
Click through for comparison shots and further commentary…
Photos and resizing
Firstly, I chose a couple photos that I’ve taken with my digital camera – a Canon IXUS 400. The original photos were of Luna Park in Melbourne (1600×1200) and the Weta Tripod in Wellington (2272×1704). I resized both photos to 500×375 (a nice size I use frequently for sharing photos on the web) with Macromedia Fireworks 8 using constrained proportions and a bicubic resampling at 72dpi. This also reduced the filesizes from around 1-2MB to 120KB, with the JPEG quality setting left untouched at 95%.
Next I uploaded them to both Picasa and Flickr. In the case of Picasa, I uploaded the Luna Park photo twice – once via the desktop app using the upload setting of “slowest upload, largest size” and once via the website upload option. The resulting images on the website were identical. For Flickr, I used the website upload option.
Here’s where it gets interesting and a little tricky if you’re not careful with what you compare. Firstly, the pics served directly from Picasa and Flickr, (click the images to visit the respective websites),
(edit: it turns out I can’t hotlink directly to the source image after all. It was working, but only because Firefox was serving the image from a cached copy. You’ll have to click through to Picasa and maximise your browser on a large screen to see the full quality photo – more on that below…)
Spot any differences? You shouldn’t be able to as they are IDENTICAL. Download both and you’ll find the filesizes are exactly the same and both have the same MD5 checksum (9da7e3955a244172661ce282a0b38982) which proves beyond doubt they are identical.
Now for the caveats. If you click through to Picasa from the top photo, you’ll need a large screen to maximise your browser to see that exact photo – I run my desktop at 1280×1024 on a 19″ monitor. If you make the browser window smaller, Picasa dynamically shrinks the image to 300×400, which is super cool, but obviously degrades the quality a little.
I was careful to embed the above photo from the full size one in the gallery, and not via the link they provide under the “Link to this photo” option in the right hand column. Using that method to link to an image, you are given four options on size – thumbnail, small, medium and large. With the “Large 800px” option, the resulting image you are given to link to is the following,
Picasa, (via link to this photo – large 800px)
Now you might be able to spot some differences (look carefully around the words “Luna Park”). This image has had its quality reduced from 95% to 79% at a resolution of 96dpi, resulting in the filesize dropping from around 124KB to 54KB. Note that ~80% is the most common quality factor used by applications that optimise photos for sharing – it’s a nice tradeoff between quality and filesize.
If you think about this for a minute, it makes good sense for two reasons – 1. it lowers the bandwidth cost for Google when images are embedded on remote sites and 2. this makes those images on remote sites load faster than if the full quality image had been embedded. As you can see the quality reduction is minimal when you’re simply sharing snapshots with friends or family.
What I haven’t looked at here is how the two services handle large photos (say 1600×1200), and what their resized photos for sharing are like quality wise – another day perhaps… While both sites give you several sizes to share, I think Flickr does it better by making the different photo sizes easier to access and preview prior to linking/sharing.
For smaller sized images such as the above, you can get at the original full quality photo on both Flickr and Picasa, but only if you’re careful at Picasa. Both sites offer smaller resized photos for sharing and embedding remotely, with Flickr doing it better by providing previews and easier links to use. Despite this, I still favor Picasa for reasons outlined in my previous post – Photo faceoff: Flickr vs. Picasa.
UPDATE: As you might have noticed above, hotlinking the way I did from Picasa doesn’t work. The comparison is not moot however, as when visiting Flickr and Picasa directly you will see the identical high quality image at both, providing Picasa hasn’t resized it down of course. For remote embedding that works(!) Flickr does allow the higher quality source to be embedded while Picasa reduces the quality to ~80%.