This paper describes a method for comparing the absorption by hemoglobin of reflected light from a range of high-intensity light-emitting diodes (LEDs) as part of the development of a system to obtain high-contrast video images of microcirculation in vivo coupled with a measurement of the relative hemoglobin oxygen saturation in micro vessels. Light from a range of high-intensity LEDs was used to image oxygenated and deoxygenated hemoglobin in vitro to measure the difference in optical densities. The LED for which the highest difference in optical density was measured was then incorporated in a prototype imaging device with illumination from a super actinic 420-nm LED and filtration of the image at 410 nm and 430 nm. This device produced high contrast-video images of microcirculation at410 nm and 430 nm. The difference in the absorption of light at the two wavelengths allowed the determination of the relative hemoglobin oxygen saturation. The proposed method is shown to be suitable for estimating the relative oxygenated hemoglobin from microvascular images.