French fries in color space
Andy Wilson’s column in the August issue of Vision Systems Design entitled “My way or the highway” (p. 80) brought back memories of a project I worked on for a french-fry manufacturer. The idea was to grade french fries using color space analysis. I implemented a custom color space transform specifically adapted to french fries, similar to what you describe. Captured images from an RGB camera were transformed from RGB space into a space in which simple limits can be applied to pixels to figure out whether they fail for “browning” on one axis and off-colors in the other two axes of a cylindrical coordinate system.
The project never took off, but we did obtain a patent and an IEEE paper from the development of the system. The patent number is 5818953, and it can be found on-line at www.google.com/patents?id=mHoCAAAAEBAJ&dq=andrew+queisser. The patent was assigned to our customer, Lamb Weston (Pasco, WA, USA; www.lambweston.com).
The IEEE paper, “Color spaces for inspection of natural objects,” was presented at the International Conference for Image Processing (www.icip2007.org) in 1997 in Santa Barbara, CA, USA. It is available to IEEE subscribers and members at ieeexplore.ieee.org/xpl/freeabs_all.jsp?arnumber=631973.
Andrew Queisser
[email protected]