A Quick Look at Quality (Google+ vs. Flickr)

I had recently taken some photos of my friend Mairi, and wanted to share them. Lately I've been using Google+ more and more (they just make it too easy to use), and photographers seem to be one of the larger groups of users.

So I decided to see what my images would look like on Google+ as compared to Flickr (my mainstay), or even 500px. I've been a Flickr user for years (I think the $25USD/year for a Pro account is a pretty good deal for what it offers), and it's been my reference for a while.

So, let's take a look!

Reference

I'm using a recent photo of my friend Mairi as a reference. Specifically, the final 100% jpg output at full size when I was done playing with it in GIMP.

GIMP portrait beauty woman
My reference image.

This is the same image I initially uploaded to Google+ and Flickr in full resolution, at 100% JPG quality, optimized, progressive, DCT Floating Point, Subsampling 4:4:4.

I resized the image in GIMP before uploading here to 550px wide, and used Sinc (Lanczos3) resizing (don't worry, I'm just putting this up here for reference), and exported as PNG using RIOT.

Method

So what I did was, after uploading the full quality image in it's final form to both Google+ and Flickr, I then went and re-downloaded the image from the same services. Google+ will resize your images to a maximum side dimension of 2048px for you (unless you upload directly through picasaweb/Picasa).

So I used the 2048px size as the output from both Flickr and Google+ (they both provide a resized version of your image at those dimensions). I brought them into GIMP, and compared them by setting one layer over the other in Difference blending mode.

To emphasize what I was seeing, I ran a simple Colors → Auto → Normalize against the difference results.

Here's the resulting Difference:

GIMP Flickr Google+ Difference Quality

Of course, anytime you run an image through a compression algorithm, there are bound to be differences in the results. It's important to keep in mind, too, that the Flickr file at 2048 pixels clocks in at about 1.4 MB in size, while the Google+ version is half that at 745 KB.

Here is a 200% crop of an area of interest from Flickr (mouseover for comparison to Google+):


200% crop from Flickr (mouseover to compare Google+)

Here's another 200% crop of the background grain from Flickr (mouseover to compare Google+):



200% crop of background grain from Flickr (mouseover for Google+ comparison)

Results

To my eye, the extra compression that Google+ is adding to the images is not good. There's some aliasing effects along sharp edges that I don't like, and areas of smooth color + grain fare very poorly. There's also some softening/smearing that occurs at the Google+ compression stage that I don't like.

Take this with a grain of salt, of course. These images are being viewed again at 200%, and pixel-peeping. For instance, here are both images resized to 550 pixels wide (Flickr first, mouseover to compare to Google+):


Flickr image at 550 pixels wide (mouseover to compare Google+)

And here is a simple 100% crop of a similar area of interest from earlier (again, Flickr first, mouseover for Google+ comparison):


I think given the choice I would opt for the Flickr version every time. It's a bigger file, but even at 2048 pixels, it's still not likely to exceed 2 MB for an image. A small price to pay to keep the viewing quality of the image a bit higher...

6 comments:

  1. I've had numerous issues with google's reprocessing. Years back there was oversharping. Lately I've had loss of contrast and detail. Subtle shades near the darker levels get crushed. I see these when I view the images online. But when going through the whole toolchain (uploaded from computer, stored on google, then down to my nexus 7) they look crisp. So obviously they are optimizing for different circumstances.

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  2. "Google+ will resize your images to a maximum side dimension of 2048px for you."

    That's not true, they let you choose to upload the full size. See https://support.google.com/plus/answer/156348?hl=en for details.

    ReplyDelete
    Replies
    1. You're right, I should clarify.

      UNLESS you use the android app, or the desktop Picasa app, in which case it will upload the full resolution image.

      This is the same as uploading to Google Drive directly (full-size).

      Also, I am comparing the resized 2048px version from Flickr and G+. So even if you upload the full-resolution image, these results are going to be the same. (For reference, I uploaded the full-resolution image to Google, and let them resize it on their side).

      Delete
  3. The links to the G+ versions seem to be broken, so mouse-over to compare just makes the image disappear, at least on my machine.

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    Replies
    1. I just re-checked and they appear to be working from my side. They may take a moment to load, have you rechecked after giving it a moment to see if it fixes it?

      Delete
  4. Hmm... Only beef with Flickr is that it requires a Yahoo! account and that requires you to give them your mobile number.

    I rather have a Photo Sharing sight with their own social features than sign up for a complete social network like Google+ just to share photos - also, the lengths Google goes through to lock you into their Social Network is too much for me (hard to share to other social sites from Google Photos), and Flickr is more widely supported in 3rd party software like Windows Photo Gallery, Photoshop Elements, etc.

    They really need to make their mobile apps better though, especially Android, Windows Phone.... Will they ever have a true Tablet app (Android, Windows RT, iOS)?

    For now, I just upload/back up to OneDrive.

    I recently went through and just deleted all my old photos (about 500) because I was tired of dealing with the managing of them and none of the photo sites were overall usable for me. Better to just not take pictures than have to deal with all the requirements, restrictions, and hoops they make you jump through to use them.

    I bought a new phone, but I barely use the camera now because there really is not "easy" way to just get and use a decent service. Seems like the best the average user can do is throw them on OneDrive or DropBox (or a [Shared] Photostream - Apple was up to something there) and move on with your life.

    ReplyDelete