A major advantage of color resolving X-ray Imaging, compared to regular X-ray imaging systems, is the capability to discriminate energy of detected X-rays. This opens the possibility to even recognize different materials in X-ray images. Three or more images are measured at different energy discrimination thresholds. The images are then analyzed using our software tools and color image is created. Colors in the image represent different elements in the sample. Color X-ray image of different painting pigments is used as an example:
|Photo of pigment stripes and grains. From left: Au for gilding and paints containing Cd, Cr, Cu, Pb and Co.||Regular X-ray image.||Color X-ray image created based on three measured frames. Each frame was taken at different energy threshold, hereafter; images were mapped to red, green and blue components of the final color image.|
Our hardware and software also allows 3D material recognition. The next image shows visualization of a 3D reconstructed volume. Various colors are representing different materials of the sample. The test sample consisted of overlapping foils of different metals (Ni, Cu, Ag and Sn). The foils were 25 µm thick. The CT projections were measured at three different energy thresholds and the RGB components of colors in the reconstructed volume were mapped to each energy threshold.
Color CT of a USB memory stick: measured with QTPX-262k detector, 40 projections, X-ray tube running at 50kVp@100µA, 3 energy thresholds used. Different colours in the visualisation correspond to different materials found in the CT reconstruction.
Vertical slices of the USB memory stick CT reconstruction.