“…Using the Sobel operator, the paper [21] was able to identify diseases in hevea tree leaves by computing the gradient of each pixel in the image. Harris and susan [22] Histogram (brightness, contrast enhancement, region of interest) [11] Sobel Operator [21], [26] De-hazing [6], [12] Robert, Prewitt, Sobel, and Laplacian of Gaussian (LoG) operator masks [24] Power-of-two terms [24] Canny edge detection [23] Gaussian-based halo-reducing filter [7], [27] Biomedical image enhancement (BIE) [8] Modified context (MCT) [20] Median filter [28] Adding image [1] Adaptive histogram equalization (AHE) [19] 2D adaptive DIP [29] Boundary discriminative noise detection (BDND) [30] Guided image filtering and Halide [31] Discrete wavelet transform (DWT) [2] Contrast, brightness enhancement, image inverting, and threshold operation [32] Gaussian-based smoothing filter [33] Particle swarm [34] Medical image algorithm [35] Out of 13 papers that implemented image enhancement in hardware, only papers [12] and [6] can be compared as only these papers employs similar algorithm. Soma and Jatoth [6] proposed hardware implementation via the use of the Xilinx Zynq-706 FPGA board, while the paper [12] proposes the Xilinx Zynq-7000 FPGA board for its hardware implementation.…”