A couple of interesting Image Processes

CyArk - Digital Archives of Physical Artifacts

from Data Mining: Text Mining, Visualization and Social Media by Matthew Hurst

This months National Geographic contains, amongst a rich array of rich data graphics, an introduction to CyArk. CyArk is a project which creates archives of cultural artifacts by recording point clouds.

CyArk is a non-profit entity whose mission is to digitally preserve cultural heritage sites through collecting, archiving and providing open access to data created by laser scanning, digital modeling, and other state-of-the-art technologies.

The resulting data sets are a little like the data found in Photosynths, but the geometry is directly captured rather than infered from imagery. Below is one of their more ambitious projects: Mount Rushmore.

 

 

Image Error Level Analysis

Error level analysis is a quick and easy image forensics method, allowing one to determine if an image has been modified by programs such as Adobe Photoshop.

It works by resaving an image at a known quality, and comparing that to the original image. As a jpeg image is resaved over and over again, its image quality decreases. When we resave an image and compare it to the original, we can guess just how many times the image has been resaved. If an image has not been manipulated, all parts of the image should have been saved an equal amount of times. If parts of the image are from different source files, they may have been saved a number of different times, and thus they will stand out as a different colour in the ELA test.

It is worth noting that edges and areas red in colour are often depicted as brighter in the ELA tests. This due to the way the photos are saved by various programs. It is not proof that image was manipulated.

If you are unsure how to interpret the results, please do not claim the results of this tool as proof of anything.