Abstract: In a method of multi-wavelength imaging internal structures of a highly turbid medium, the internal structures are imaged at each one of a set of at least two predetermined wavelengths, to generate a corresponding set of respective images. The set of images are then merged to generate a corresponding fused image.

Abstract: In general, the spatial resolution and repeatability of results using infrared detectors for examining printed circuit cards has been so poor that the devices have failed to achieve commercial success. These problems are overcome by a system including an isothermal enclosure for receiving a card to be tested, an infrared camera in the chamber defined by the enclosure, sensors for monitoring the temperature of the card and ambient temperature conditions in the chamber to derive signals indicative of the temperatures, and a computer connected to the camera and to the sensors for examining all signals to produce a three dimensional image of the sample, variations in the image from sample to sample being indicative of an anomaly in a sample.