Cultural Heritage Imaging

Mustafa Umut Sarac submitted a new resource:

(there was a url link here which no longer exists) - Cultural Heritage Imaging

Its a multiple led array light source filtered by White paper. Same height with camera and around 35 degrees to the subject. Text taken from a website.

Illumination: EV™ LED Illumination System

A revolutionary EV™ LED illumination system provides unprecedented opportunities in imaging and image quality. This system enables imaging in multiple distinct narrow spectral bands or combinations of spectral bands over a range of wavelengths from the near ultraviolet to the near infrared....

Click to expand...

(there was a url link here which no longer exists)

Color Capture With a Monochrome Sensor and LED Illumination
While the human color vision system is functionally tri-stimulus, our retinal spectral response curves can't be replicated by a simple set of 3 band-pass filters. Somewhere in the range of 5-8 bands are required to get enough spectral information to make a good match to human vision. Attempts to make practical systems utilizing multiple band capture with color filters between the scene and the sensor have not been successful (for reasons that can be readily appreciated).

By coming at the problem from a different angle, namely, creating the color bands at the source of the light (using LED's), the EV™ system solves the intractable practical problems.

Capturing sufficient perfectly registered and highly repeatable spectral bands is an enabling technology for deploying semi-automated, high-quality color reproduction. With tri-stimulus capture, color matching over a practical range of commonly encountered dyes, pigments, plastics, and other materials is sufficiently poor that individual, scene-specific color adjustments must be performed to obtain the desired quality. This color-matching step is sufficiently time consuming and costly that it is practical to create high-quality color reproductions of only the most expensive originals. The EurekaVision™ approach can dramatically reduce the amount of labor intensive post-processing of the image data and provide highly accurate color reproduction of a very wide range of difficult subjects.

UV 365nm
Visible 445, 470, 505, 530, 570, 617, 625nm
Infrared 700, 735, 780, 870, 940, 1050 nm

These narrow band led lights are sold at ebay for few cents or dollars each, I saw 3 watt 445nm for 1 dollar or less.

umut