FPGA Implementation of Low-Light Enhancement Algorithm_ To Enhance Low-Light Images/Videos Matlab

This example performs LLE by inverting an input image and then applying a de-haze algorithm on the inverted image.

After inverting the low-light image, the pixels representing non-sky region have low intensities in at least one color channel.

The algorithm consists of six stages. Step 1: Scaling & Inversion The input image   is converted to range [0,1] by dividing by 255 and then inverting pixel-wise. Step 2: Dark Channel Estimation The dark channel is estimated by finding the pixel-wise minimum across all three channels of the inverted image. Step 3: Refinement The airlight image from the previous stage is refined by iterative smoothing. This stage consists of five filter iterations with a 3-by-3 kernel for each stage. Step 4: Non-Linear Correction To reduce over-enhancement, the refined image is corrected using a non-linear correction. Step 5: Restoration Restoration is performed pixel-wise across the three channels of the inverted and corrected image. Step 6: Inversion To obtain the final enhanced image, this stage inverts the output of the restoration stage, and scales to the range [0,255].

The figure shows the input image and the enhanced output images obtained from the LLESimplified subsystem and the LLEHDL subsystem. Click here to get the simulink file: https://drive.google.com/file/d/1nBBRRzjqXsKmImOCqdXWTZ8NXM6hmi3m/view?usp=sharing

Implementation of Haze Removal Algorithm to Enhance Low-Light Images Using Matlab

This example shows how to enhance low-light images using an algorithm suitable for FPGAs.

Haze removal or image dehazing is required in real-world weather conditions to obtain a fast and high-quality hazy free image which is used in various fields like satellite systems and aircraft systems.

Some of the wide important areas in which the haze removal methods used are air- crafts, remote sensing, intelligent transportation systems, underwater image processing, Object detection, outdoor surveillance, railway systems, aerial imagery, computational photography/vision applications, video analysis and recognition, image classification, military and defense surveillance system, etc. Example Code: % Import an RGB image captured in low light. A = imread('lowlight_21.jpg'); % Invert the image. AInv = imcomplement(A); % Apply the dehazing algorithm. BInv = imreducehaze(AInv,'ContrastEnhancement','none'); % Invert the results. B = imcomplement(BInv); %Display the original image and the enhanced images, side-by-side. montage({A,B}); click here to download the Matlab Livescript file: https://drive.google.com/file/d/1S8iBE42W0akwTQp2BksTsSd-NRb5MvV5/view?usp=sharing