Contrast enhancement using histogram equalization with bin underflow and bin overflow
نویسندگان
چکیده
The histogram equalization (HE) is a widely used contrast enhancement method. But what is missing fromthe HE is a mechanism to control the rate of enhancement. The enhanced image always follows the uniform distribution. This paper presents a simple enhancement rate control mechanism for the HE. The gradient of the mapping function is controlled hy putting contraints on the probability density function with the bin underilow (BU) and bin overflow (BO). The BUBO operation can provide the rate ofenhancement from non to the full HE with a single parameter. With the enhancement rate control mechanism available, the HE can he used to perform image processing tasks such as hlacWwhite level stretch or automatic brightness control as well as variable rate contrast enhancement.
منابع مشابه
Efficient Reversible Watermarking Technique with Contrast Enhancement for Color Images
In this paper histogram bin shifting based reversible data hiding algorithm for color images has been proposed. In this technique binary bits are embedded directly by addition and subtraction in two highest bin chosen and this process is repeated in modified histogram. A location map is generated by pre -processing to prevent the unnecessary overflow and underflow. All other pixels except two h...
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 کاملA Location-Map Free Reversible Watermarking With Capacity Control
Reversible watermarking techniques enable the extraction of the embedding bits from a watermarked image in a lossless way. It exploits the high spatial correlation among neighboring pixels. Application in reversible watermarking includes military and medical images. However, images occurs overflow or underflow problems during the imbedding process. Since pixels value may be out of range between...
متن کاملContrast Enhancement of Portal Images with Adaptive Histogram Clip
The radiotherapy is a widely used and effective method for cancer treatment where a highenergy beam is targeted at the tumor volume. To properly deliver the required radiation to the tumor and to prevent surrounding tissue from destruction, the beam has to be shaped as prescribed by the physician. This requires registration of two images: a reference image and an image obtained during the radia...
متن کاملEnhanced Breast Mammograms Classification using Bayesian Classifier
Mammography is a particular type of imaging that uses a low-dose xray system to examine breasts. A mammography exam, called a mammogram, is used to aid in the early detection and diagnosis of breast diseases in women. In this paper, we have proposed a method that consists of combination of different methods. First we have performed enhancement on breast mammogram to enhance the image quality. W...
متن کامل