Modified demosaicing scheme on FPGA using Xilinx System Generator
28 May 2015-pp 517-522
TL;DR: In proposed approach, bilinear interpolation with sharpening filter is used for CFA demosaicing, which has low computational complexity and high image processing speed; hence the design can be implemented in real time low cost embedded system applications.
Abstract: The recent technology in digital cameras uses single CCD or CMOS sensors as a substitute to three separate RGB sensors Color camera consists of single CCD or CMOS sensor with an overlaid Color Filter Array (CFA) This paper proposes a novel approach of CFA demosaicing In proposed approach, bilinear interpolation with sharpening filter is used for CFA demosaicing The proposed work tested on Virtex 5 FPGA in real time mode as well as on true color test image database Xilinx System Generator (XSG) has been used for system modeling and design implemented on target device FPGA The results of proposed FPGA based work improved than software based simple bilinear interpolation, edge directed interpolation and adaptive color plane interpolation methods and comparative to modified adaptive color plane interpolation method The proposed approach has low computational complexity and high image processing speed; hence the design can be implemented in real time low cost embedded system applications
Citations
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01 Sep 2016
TL;DR: This paper presents how to generate the V HDL code of the backstepping control of a doubly fed induction generator required for programming an FPGA without knowledge of VHDL programming.
Abstract: This paper presents how to generate the VHDL code of the backstepping control of a doubly fed induction generator required for programming an FPGA without knowledge of VHDL programming. This control strategy will be developed by the Xilinx System Generator (XSG) tool integrated in matlab/simulink environment. The importance of this technique is to enjoy the benefits of Simulink and XSG. The first simulates the proposed control algorithm and the second generates the VHDL code of discrete algorithm that can subsequently be implemented on FPGA.
3 citations
Cites methods from "Modified demosaicing scheme on FPGA..."
...Finally, the simulation results are depicted using Matlab/Simulink....
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...The XSG tool is used to produce a model that will immediately work on the equipment when completed and validated [7]....
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...Once the model is completed, the VHDL code generated by the tool XSG reproduces the same behavior observed on Matlab/Simulink [6-7]....
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...DEVELOPMENT OF BACKSTEPPLING CONTROL USING XILINX SYSTEM GENERATOR In this section, we focus on the software implementation of backstepping control using Xilinx System Generator that is a toolbox developed by Xilinx society to be integrated into the Matlab/Simulink environment....
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01 Dec 2020
TL;DR: A color interpolation algorithm based on image gradient direction and color difference that has been applied to the actual Xilinx’s FPGA platform, a real-time speed of 120 MHz, enabling real- time image color Interpolation.
Abstract: To quickly and efficiently achieve a high-quality color image on the embedded platform, designed and used FPGA to complete Bayer pattern image Color interpolation. In this paper, we proposed a color interpolation algorithm based on image gradient direction and color difference. The algorithm calculates the G component according to the gradient value and color difference at the pixel to be interpolated, and then calculates the missing R component and B component based on the G component interpolation. Finally, the pixels of the image boundary area are interpolated. Tested on the Kodak dataset, the experimental results show that the subjective visual quality and objective image quality evaluation of the algorithm is superior to the conventional algorithm. On the other hand, and reduce problems such as image aliasing and edge blurring. The proposed algorithm has been applied to the actual Xilinx’s FPGA platform, a real-time speed of 120 MHz, enabling real-time image color Interpolation.
2 citations
References
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TL;DR: A novel approach to demosaicing based on directional filtering and a posteriori decision is presented, which gives good performance even when compared to more demanding techniques.
Abstract: Most digital cameras use a color filter array to capture the colors of the scene. Downsampled versions of the red, green, and blue components are acquired, and an interpolation of the three colors is necessary to reconstruct a full representation of the image. This color interpolation is known as demosaicing. The most effective demosaicing techniques proposed in the literature are based on directional filtering and a posteriori decision. In this paper, we present a novel approach to this reconstruction method. A refining step is included to further improve the resulting reconstructed image. The proposed approach requires a limited computational cost and gives good performance even when compared to more demanding techniques
207 citations
26 Feb 2009
TL;DR: The proposed FPGA demosaick algorithm achieves reasonable image quality, and it is an economic alternative for smart camera devices.
Abstract: Current image sensors offer a raw output that incorporates a bayer color filter pattern, and additional processing is required to obtain a full color image. This paper presents a bilinear interpolation algorithm to demosaick images with bayer color pattern; the algorithm is implemented in a single Field Programmable Gate Array (FPGA) device using a pipelined architecture. A comparison between images obtained with the FGPA-based interpolation and a software-based interpolation using Matlab demosaicking function is presented. The proposed FPGA demosaick algorithm achieves reasonable image quality, and it is an economic alternative for smart camera devices
14 citations
03 Apr 2013
TL;DR: CFA demosaicing is a digital image process used to reconstruct full color image from the incomplete color samples, which is used in digital cameras, camcorders and scanners to create a color image.
Abstract: Color Filter Array (CFA) is a mosaic of tiny color filters placed over the pixels of an image sensor to capture information. The most common filter is Bayer's filter. A Bayer filter arranges RGB color filters on a square grid of photo sensors. The color filters is used in single chip image sensors which is used in digital cameras, camcorders and scanners to create a color image. Digital still cameras (DSC) are widely used nowadays and it has a single chip CCD image sensor in order to reduce the cost. These single chip cameras use CF A to obtain different color information. Since only one component is available (Either R or G or B) at each pixel, the other two missing color components have to be estimated from the neighboring pixels. The process is called as CFA demosaicing. Demosaicing is a digital image process used to reconstruct full color image from the incomplete color samples. Various types of demosaicing algorithms are linear and bilinear interpolation, bicubic interpolation cubic spline interpolation, homogeneity directed demosaicing algorithm, higher order interpolation and higher order extrapolation etc. Bilinear interpolation algorithm for a 64*64 image is simulated in Xilinx.
12 citations
01 Dec 2009
TL;DR: A color interpolation design based on bilinear interpolation and a new real-time median filter with low memory requirements is presented and increases the performance by about 4 dBs with respect to a simple bilinears interpolation system.
Abstract: This High-definition and real-time video is one of the features that is being explored for the next generation of telecommunication systems. Most commercial video-cameras obtain Bayer images that have to be converted to RGB ones. Even though most of these cameras are able to perform this conversion internally, when working with high-definition images this process is quite slow and impedes real-time applications. Therefore, it is interesting to explore high-speed solutions that can perform Bayer to RGB conversion outside the camera. This paper presents a color interpolation design based on bilinear interpolation and a new real-time median filter with low memory requirements. The system is designed for real-time high-definition video systems although it can be used for single frame interpolation. The median filter proposed increases the performance by about 4dBs with respect to a simple bilinear interpolation system. This improvement in the performance is obtained without adding extra delay or memory to the classical bilinear interpolation. It only increases lightly the area. The memory consumption is reduced to two frame lines and it is implemented in less than 30% of the area available in a Spartan III S500 FPGA, working at almost 100MHz. The system can work with high resolution frames up to 1280×1024 pixels.
10 citations
16 Jul 2012
TL;DR: In this work, an improved edge detection bilinear interpolation algorithm is used to calculate R and B components for Bayer CFA digital cameras and can achieve a higher PSNR compare to three conventional methods.
Abstract: Digital cameras mostly use a color filter array (CFA) to capture the colors of the scene. To render a full-color image, numerous color interpolation algorithms are proposed to recalculate full resolution R, G and B components. Based on the image correlation and simple edge detection, we propose a color interpolation scheme for Bayer CFA digital cameras. In our proposed scheme, an improved edge detection bilinear interpolation algorithm is used to calculate R and B components. Simulation results show that our proposed scheme can prevent from sudden change, flatten, less distortion effectively, and preserve vein and detail as much as possible. In edge areas of the test images, not only the advantage of simpleness in bilinear algorithm is retained, but also the number of pixels involved in the calculation is reduced. Moreover, our proposed scheme can also achieve a higher PSNR compare to three conventional methods.
2 citations
"Modified demosaicing scheme on FPGA..." refers methods in this paper
...In the experiment, the proposed algorithms are compared with software based four conventional methods [2]....
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...The adaptive interpolation algorithms use the correlation principle, such as gradient-based edge oriented interpolation and the adaptive homogeneity-directed demosaicing algorithms [2]....
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