In a post today on the Panoramio blog, co-founder Eduardo Manchón, says that after four and a half years working on the service, it’s time to leave. Google acquired Panoramio in mid-2007 and Manchón has been there ever since, running the service. He notes that, “Acquisitions can be complicated, and the private nightmare of a founder is the site not surviving the process, but after some time Panoramio feels very comfortable at Google.”

Panoramio has certainly gained a lot of exposure thanks to Google. It’s heavily featured not only in Google Earth, but also in Google Maps. The service claims to have over 20 million high quality photos in Google’s databases, which makes it much smaller than Flickr, Facebook, or even Google’s own Picasa, but the difference is that all Panoramio photos are geolocated, which makes them very useful for Google’s mapping projects. Under Google, the Panoramio photo collection has growth from about 2 million to this 20 million number.

Manchón’s exit seems to more closely mirror that of Jyri Engeström, the co-founder of Jaiku, who left Google last October. Even though Jaiku was another service Google managed to run into the ground, Engeström claimed that he enjoyed his time at Google but simply wanted to make new meaningful products. This is similar to Manchón’s stated reason for leaving, which is to join the “new hyperlocal Q&A site Askaro.com,” he writes to us.

Another Googler, Gerard Sanz, formerly of the Blogger team, will take over running the Panoramio community.

Image recognition is still one of those things that humans find easy to do but computers keep stumbling over. Some Google researchers published a paper describing progress they are making in teaching computers how to identify famous landmarks, which may eventually be applied more broadly to image search in general.

In a blog post, Jay Yagnik, the head of Computer Vision Research at Google, writes:

While we’ve gone a long way towards unlocking the information stored in text on the web, there’s still much work to be done unlocking the information stored in pixels.

In the experiment, the researchers fed “an unnamed, untagged picture of a landmark” found on the Internet and the system would spit back the name and location of the landmark, such as the Acropolis in Greece. Each untagged photo was be compared to 40 million GPS-tagged images on Picasa and Panoramio (both owned by Google), as well as related photos found through Google Image Search. Using clustering and new image indexing techniques, the Google researchers were able to identify untagged photos of the same landmarks from different angles and under various lighting conditions.

The researchers report that their system can identify 50,000 landmarks with 80 percent accuracy. I’m not sure that’s quite good enough to even roll that out in a beta product, but if Google can get it to 90 percent or 95 percent that would start to be consumer-friendly. Over the past few years, there’s been a lot of progress in image recognition, especially with facial recognition For instance, Face.com does a particularly good job with Facebook photos. But buildings and objects may be pose a different set of image-recognition challenges.

Microsoft’s Photosynth is undeniably gorgeous – it lets users “walk” through various locales by stitching together thousands of user-submitted photos to create a virtual 3D environment. Unfortunately, up until today this experience has only been available to Windows users.

Cue Panoramio, a Spanish photo site that Google acquired in May 2007. Panoramio has just launched a new “Look Around” feature that seems like a toned down (but still impressive) version of Photosynth. And because it’s in Flash, you’ll be able to try it out on your Mac.

The site has stitched together photos from areas with high image density (mostly landmarks and city squares) to create its version of walk-through albums. At launch users can choose from sites including the top of the Empire State Building, the Sydney Opera House, and the Taj Mahal.

Users can even create their own “Look Around” destinations by taking 10-20 photos of their favorite places. Panoramio’s system indexes new photos and searches for matches every two weeks.

For more information and available destinations, check out Frank Taylor’s blog and the video below.