| 摘要 |
A method for high dynamic range compression uses a modified cumulative histogram as a compression curve. This curve is computed from the cumulative histogram of the image with constraints that the local derivative on the curve does not exceed a certain limit. The limit is fixed along the curve or the limit is variable, taking into account noise characteristics at various pixel values. To provide appropriate detail preservation, a smoothing filter is used to separate the image into an illumination image, referred to as a base image, and a detail image, and the compression curve is applied to the base image only. The compression method provides high dynamic range compression of the image while preserving the global contrast perception. Conventional global algorithms for high dynamic range compression are not capable of achieving this result. The proposed high dynamic range compression method also minimizes noise amplification while lightening the dark areas during image compression.
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