I. Histogram Equalization (HE) & Matlab source

Histogram equalization is a method for modifying the image based on its histogram. The primary purpose is for contrast enhancement. Please read the following paper for details about the algorithm: “A Histogram Modification Framework and Its Application for Image Contrast Enhancement” [DOI].

The idea of HE is to create a function that makes the dark pixels a bit brighter and the bright pixels a bit darker, thus stretching out, or balancing out, the histogram. For this project, we prepared a Matlab source for HE demonstration: download. To run the demo, first open your Matlab, then go to the Matlab/src/ folder and you’ll see the BasicHE.m file. Executing by: BasicHE(<image path>); for example: BasicHE('Standard Test Images\misc\4.1.01.tiff') and you’ll get this result:

II. FPGA sources

Several FPGA demos are prepared. And they are given with some options as follows.

II. a) Display using on-board LCD

These FPGA demos using on-board LCD to display the video. The available sources are:

II. b) Display using VGA

These FPGA demos using VGA to display the video. The available sources are:

II. c) Display using VGA, with HE

This FPGA demo is similar to the previous sub-section’s Arrow SoCKit (HD). The only difference is that the HE is displayed on the same monitor together with the video stream.

II. d) Display using VGA, with HE and auto-exposure

This FPGA demo is similar to the previous sub-section’s Arrow SoCKit (HE). The only difference is that now it has the feature of auto-exposure feeding back to the camera.

III. Demonstration

The following demo is done with the SoCKit_Camera_VGA_HD_HEdisplay_autoExposure.rar. The setting for screen display is given as follows:

The demonstration:

IV. Citation

If you use the sources from this page in your published work, please cite the following. As plain text:

Takahiro Hosaka, Trong-Thuc Hoang, Van-Phuc Hoang, Duc-Hung Le, Katsumi Inoue, and Cong-Kha Pham, "Live Demonstration: Real-time Auto-exposure Histogram Equalization Video-system Using Frequent Items Counter," in Proc. of IEEE Int. Symp. on Circ. and Syst. (ISCAS), Sapporo, Japan, May 2019, pp. 1-1.

As bib-entry:

@inproceedings{HosakaFIC2019,
  author    = {{Takahiro Hosaka, Trong-Thuc Hoang, Van-Phuc Hoang, Duc-Hung Le, Katsumi Inoue, and Cong-Kha Pham}},
  title     = {{Live Demonstration: Real-time Auto-exposure Histogram Equalization Video-system Using Frequent Items Counter}},
  booktitle = {{IEEE Int. Symp. on Circ. and Syst. (ISCAS)}},
  address   = {{Sapporo, Japan}},
  year      = {{May 2019}},
  pages     = {1--1}
}