Dynamic Contrast Enhancement Using Multiple and Clipped Histogram Equalization
نویسندگان
چکیده
Histogram equalization (HE) is one of the common methods for improving contrast in digital images. However, HE may introduce some unnecessary visual deterioration while enhancing image. One of the solutions to overcome this weakness is by preserving the mean brightness of the output image. This paper proposes a new method, known as dynamic contrast enhancement using multiple and clipped histogram equalization (DCMHE). The proposed method first smoothes the global histogram and assigns each partition to a new dynamic range via optimal thresholds, and then clipping process is implemented to each sub-histogram. At last step, the conventional HE is implemented to each sub-histogram and the output image is normalized to the input mean brightness. Simulation results for several test images show that the proposed method enhances the contrast while preserving mean brightness. Copyright © 2013 IFSA.
منابع مشابه
Multi Histogram Equalization Based Contrast Enhancement for Images
The fundamental and important pre-processing stage in image processing is the image contrast enhancement technique. Histogram equalization is an effective contrast enhancement technique and thus in this paper, a histogram equalization based technique called Quadrant Dynamic with Automatic Plateau Limit Histogram Equalization (QDAPLHE) is introduced. In this method, a hybrid of dynamic and clipp...
متن کاملStandard Intensity Deviation Approach based Clipped Sub Image Histogram Equalization Algorithm for Image Enhancement
The limitations of the hardware and dynamic range of digital camera have created the demand for post processing software tool to improve image quality. Image enhancement is a technique that helps to improve finer details of the image. This paper presents a new algorithm for contrast enhancement, where the enhancement rate is controlled by clipped histogram approach, which uses standard intensit...
متن کاملDensity-Based Histogram Partitioning and Local Equalization for Contrast Enhancement of Images
Histogram Equalization technique is one of the basic methods in image contrast enhancement. Using this method, in the case of images with uniform gray levels (with narrow histogram), causes loss of image detail and the natural look of the image. To overcome this problem and to have a better image contrast enhancement, a new two-step method was proposed. In the first step, the image histogram is...
متن کاملQuadrant Dynamic with Automatic Plateau Limit Histogram Equalization (qdaplhe)
In image processing, image enhancement is used to improve the image quality through a broad range of techniques such as contrast enhancement, color enhancement, dynamic range expansion and edge emphasis and so on. In consumer electronics, many histogram equalization based methods have been used in recent years. Many of these methods are complicated to implement and also some method will produce...
متن کاملIllumination based Sub Image Histogram Equalization: A Novel Method of Image Contrast Enhancement
A novel Illumination based Sub-Image Histogram Equalization (ISIHE) method for contrast enhancement for low illumination gray scale images is presented in this paper. As the main crux of paper, illumination thresholds are computed and used to divide the original image into sub-images of different intensity levels. To control the enhancement rate, the histogram is clipped using a threshold value...
متن کامل