Software claims world record by solving 400-piece jigsaw puzzle

London, May 22 : A new software developed by scientists at the Massachusetts Institute of Technology, has created a new world record by solving a 400-piece jigsaw puzzle.

A Danish team established the previous record of 320 pieces in 2008, but their computer could only solve puzzles with simple cartoon-style pictures featuring clear shapes and a limited number of colours.

Developed by Taeg Sang Cho and colleagues, the new program can cope with any image, including photographs of outdoor scenes.

The team diced up 5-megabyte pictures into 400 squares and fed them into the software. Just as a human might, the computer analyses the predominant colours to try to work out what kind of image is hidden in the jumble.

It then refers to a database of existing images to roughly arrange the pieces in their likely positions.

For example, a mix of green, grey and blue pieces might imply a landscape scene with grass at the bottom, buildings in the middle and sky at the top.

After guessing the rough arrangement for the pieces, the software then examines the pixel colour values along the boundaries of each piece and finds those on other nearby pieces that match the closest. It then takes a best guess at the likely neighbouring piece.

The strategy is a good one—the computer completed the 400-piece puzzle in just 3 minutes.

Because the software is good at finding image pieces that blend well, Cho hopes it will one day help image-editing packages like Photoshop make manipulated pictures look more realistic.

"If you move a person from one side of a picture to another, our algorithm could highlight the fact that the image will jar if the pixel values are too different," New Scientist quoted Cho as saying.

The team will present their work at the IEEE Conference on Computer Vision and Pattern Recognition in San Francisco next month.