This paper proposes an automatic image correction method for portrait photographs, which promotes consistency of facial skin color by suppressing skin color changes due to background colors. In portrait photographs, skin color is often distorted due to the lighting environment (e.g., light reflected from a colored background wall and over-exposure by a camera strobe), and if the photo is artificially combined with another background color, this color change is emphasized, resulting in an unnatural synthesized result. In our framework, after roughly extracting the face region and rectifying the skin color distribution in a color space, we perform color and brightness correction around the face in the original image to achieve a proper color balance of the facial image, which is not affected by luminance and background colors. Unlike conventional algorithms for color correction, our final result is attained by a color correction process with a guide image. In particular, our guided image filtering for the color correction does not require a perfectly-aligned guide image required in the original guide image filtering method proposed by He et al. Experimental results show that our method generates more natural results than conventional methods on not only headshot photographs but also natural scene photographs. We also show automatic yearbook style photo generation as an another application.
翻译:本文建议对肖像照片采用自动的图像校正方法,通过抑制背景颜色导致的肤色变化,促进面部皮肤颜色的一致性。在肖像照片中,肤色经常由于照明环境而扭曲(例如,彩色背景壁上的光和相机色罗贝过度曝光),如果照片与另一种背景颜色人为地结合,则强调这种颜色变化,从而产生非自然合成的结果。在我们的框架内,在粗略地提取面部区域并在颜色空间中纠正皮肤分布后,我们在原始图像上进行色和亮度校正,以实现面部图像的适当色平衡,而面部图像不受光照和背景颜色的影响。与常规的彩色校正算法不同,我们的最后结果是通过带导游图像的彩色校正程序实现的。特别是,我们为颜色校正而引导的图像过滤不需要在He等人提议的原始指南图像过滤方法中所要求的完全一致的指南图像。实验结果显示,我们的方法不仅在头部照片上,而且在自然场照片上产生比常规方法更自然的结果。我们还显示另一个自动生成。