It's virtually impossible for such companies to monitor hundreds of thousands of pages created by disparate customers around the world. But government agencies, attorneys and consumer groups are increasingly shifting the burden of cleaning up the smut from the individual offenders to the businesses that enable them to operate. ImageFilter software classifies visual information by color, texture, shape and spatial configuration. It then analyzes the data to create a sort of visual thumbprint for each image that can be compared to other images that may be perceived as pornographic. If a client's server is hosting a questionable image, ImageFilter will send an email alert to that client.
Conventional filters detect offensive words or phrases in blocks of text.
Such filters are unreliable and unable to keep up with Internet slang that can sneak past them. Few filters can detect lewd art or photos because a photo's pixels are far more complicated to analyze than blocks of text. Alex Moha, vice president of business development for LookThatUp, said ImageFilter would be perfect for companies such as eBay, which hosts thousands of products posted by individuals. But images are much more difficult to monitor than text. An e-tailer specializing in toys for preschoolers, by contrast, might pick an acceptance rating of five or lower.