英语论文网

ime. Skin color is one of the most important features in the human face. Feature-based face detection techniques may use skin color information to detect faces in color images having complex background [3]. The skin detector detects whether certain regions in a color image represent human skin or not. It must define certain decision rules to discriminate between skin and non-skin pixels. To build these rules, a human skin model must be built. Several skin color-modeling methods have been introduced. The selection of the color space that will be used in modeling skin color is very important; it is well known that different people have different skin color appearance, but these differences lie mostly in the color intensity not in the color itself. That is why many skin detection methods drop the luminance component of the color space. Dropping the luminance component achieves two important goals; first the model will be independent of the differences in skin appearance that may arise from the difference in human race, or the difference in the lighting of the image; second the color space dimensions will be reduced so the calculations would be easier. There are lots of color spaces that have been used in early work of skin detection, such as RGB, normalized RGB, YCbCr, HSI [4]. Although RGB color space is one of the most used color spaces for processing and storing digital images, it is not widely used in skin detection algorithms because the chrominance and luminance components are mixed. Normalized RGB and YCbCr are often used in face detection method.

 

Face Detection using YCbCr Color Space

 

YCbCr color space has been defined in response to increasing demands for digital algorithms in handling video information, and has since become a widely used model in a digital video. It belongs to the family of television transmission color spaces. The family includes others such as YUV and YIQ. YCbCr is a digital color system, while YUV and YIQ are analog spaces for the respective PAL and NTSC systems. These color spaces separate RGB (Red-Green-Blue) into luminance and chrominance information and are useful in compression applications however the specification of colors is somewhat unintuitive. The YCbCr components are used, where in the YCbCr color space, the luminance information is contained in Y component; and, the chrominance information is in Cb and Cr. Many research studies found that the chrominance components of the skin-tone color are independent of the luminance component [5]. Hence, in this implementation, the Cb, Cr components are used to model the distribution of skin colors. The RGB components were converted to the YCbCr components using the following formula [6].

 

Y = 0.299R + 0.587G + 0.114B

 

Cb = -0.169R - 0.332G + 0.500B (1)

 

Cr = 0.500R - 0.419G - 0.081B

 

In this system, author build a skin color model based on 本论文由英语论文网提供整理，提供论文代写，英语论文代写，代写论文，代写英语论文，代写留学生论文，代写英文论文，留学生论文代写相关核心关键词搜索。