No abstract

In this paper we describe an automated method for the enhancement of digital photographic images. Th enhancement incorporates the basic photographic principle that films have best detail in mid-tones and suppressec detail toward the extremes. This means that the subject or the visually strong areas must comprise of mid-tones ir order to have good detaiL Hence appropriate regions of visual significance within an image are first identified base on the features of focus, contrast, and texture. Enhancement of the image then follows by a gray level transformation of different pixels using a simulated exposure-density curve of photographic films. The enhancemeni is influenced strongly by the visually significant areas rather than the entire image (global statistics). This al1ow the subject or important areas to be enhanced to an optimum level (mid-tones) rather than achieving good overall balance but with a dull (over-exposed or underexposed) subject.