Image Enhancement Using Modified Histogram and Log-Exp Transformation
An effective method to enhance the contrast of digital images is proposed in this paper. A histogram function is developed to make the histogram curve smoother, which can be used to avoid the loss of information in the processed image. Besides the histogram function, an adaptive gamma correction for...
| Main Authors: | , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2019-08-01
|
| Series: | Symmetry |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2073-8994/11/8/1062 |
| _version_ | 1798026930955485184 |
|---|---|
| author | Liyun Zhuang Yepeng Guan |
| author_facet | Liyun Zhuang Yepeng Guan |
| author_sort | Liyun Zhuang |
| collection | DOAJ |
| description | An effective method to enhance the contrast of digital images is proposed in this paper. A histogram function is developed to make the histogram curve smoother, which can be used to avoid the loss of information in the processed image. Besides the histogram function, an adaptive gamma correction for the histogram is proposed to stretch the brightness contrast. Moreover, the log-exp transformation strategy is presented to progressively increase the low intensity while suppressing the decrement of the high intensity. In order to further widen the dynamic range of the image, the nonlinear normalization transformation is put forward to make the output image more natural and clearer. In the experiment on non-uniform illumination images, the average contrast per pixel (CPP), root mean square (RMS), and discrete entropy (DE) metrics of the developed approach are shown to be superior to selected state-of-the-art methods. |
| first_indexed | 2024-04-11T18:43:04Z |
| format | Article |
| id | doaj.art-8be066932ece4863a8b66b991e1456ea |
| institution | Directory Open Access Journal |
| issn | 2073-8994 |
| language | English |
| last_indexed | 2024-04-11T18:43:04Z |
| publishDate | 2019-08-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Symmetry |
| spelling | doaj.art-8be066932ece4863a8b66b991e1456ea2022-12-22T04:08:54ZengMDPI AGSymmetry2073-89942019-08-01118106210.3390/sym11081062sym11081062Image Enhancement Using Modified Histogram and Log-Exp TransformationLiyun Zhuang0Yepeng Guan1School of Communication and Information Engineering, Shanghai University, Shanghai 200444, ChinaSchool of Communication and Information Engineering, Shanghai University, Shanghai 200444, ChinaAn effective method to enhance the contrast of digital images is proposed in this paper. A histogram function is developed to make the histogram curve smoother, which can be used to avoid the loss of information in the processed image. Besides the histogram function, an adaptive gamma correction for the histogram is proposed to stretch the brightness contrast. Moreover, the log-exp transformation strategy is presented to progressively increase the low intensity while suppressing the decrement of the high intensity. In order to further widen the dynamic range of the image, the nonlinear normalization transformation is put forward to make the output image more natural and clearer. In the experiment on non-uniform illumination images, the average contrast per pixel (CPP), root mean square (RMS), and discrete entropy (DE) metrics of the developed approach are shown to be superior to selected state-of-the-art methods.https://www.mdpi.com/2073-8994/11/8/1062contrast enhancementmodified histogramgamma correctionlog-exp transformationnonlinear normalization |
| spellingShingle | Liyun Zhuang Yepeng Guan Image Enhancement Using Modified Histogram and Log-Exp Transformation Symmetry contrast enhancement modified histogram gamma correction log-exp transformation nonlinear normalization |
| title | Image Enhancement Using Modified Histogram and Log-Exp Transformation |
| title_full | Image Enhancement Using Modified Histogram and Log-Exp Transformation |
| title_fullStr | Image Enhancement Using Modified Histogram and Log-Exp Transformation |
| title_full_unstemmed | Image Enhancement Using Modified Histogram and Log-Exp Transformation |
| title_short | Image Enhancement Using Modified Histogram and Log-Exp Transformation |
| title_sort | image enhancement using modified histogram and log exp transformation |
| topic | contrast enhancement modified histogram gamma correction log-exp transformation nonlinear normalization |
| url | https://www.mdpi.com/2073-8994/11/8/1062 |
| work_keys_str_mv | AT liyunzhuang imageenhancementusingmodifiedhistogramandlogexptransformation AT yepengguan imageenhancementusingmodifiedhistogramandlogexptransformation |