Robust color and shape measurement of full color artifacts by RGB fringe projection

Abstract

A novel method is presented to simultaneously measure shape and color information of artifacts containing color features. The technique operates by projecting composite red, green, and blue fringe patterns onto the surface of colorful objects. Theoretical analysis proves that there is no crosstalk between color channels during phase calculation by phase-shifting algorithm when three fringe patterns with the same fringe number are coded into red, green, and blue channels to form a composite RGB fringe pattern image. The color channel giving the maximum modulation depth at each pixel is used to measure shape information. Since three color channels are used, color information of the object surface can be extracted with high dynamic range from the same fringe pattern images. Using the recently developed color fringe projection system, composite RGB fringe patterns are projected onto colorful objects to test the proposed method. The experimental results show that the range of colors that can be measured and that shape and color information of colorful objects can be reliably obtained.