没有合适的资源?快使用搜索试试~ 我知道了~
sobel算子图像边缘检测研究外文翻译.docx
1.该资源内容由用户上传,如若侵权请联系客服进行举报
2.虚拟产品一经售出概不退款(资源遇到问题,请及时私信上传者)
2.虚拟产品一经售出概不退款(资源遇到问题,请及时私信上传者)
版权申诉
0 下载量 150 浏览量
2023-02-10
15:12:16
上传
评论
收藏 2.04MB DOCX 举报
温馨提示
试读
31页
cs
资源推荐
资源详情
资源评论
sobel 算子图像边缘检测研究外文翻译
Real-time FPGA Based Implementation of Color
Image Edge Detection
Abstract— Color Image edge detection is very basic and important
step for many
applications such as image segmentation, image analysis, facial
analysis, objects identifications/tracking and many others. The main
challenge for real-time implementation of color image edge detection is
because of high volume of data to be processed (3 times as compared to
gray images). This paper describes the real-time implementation of Sobel
operator based color image edge detection using FPGA. Sobel operator is
chosen for edge detection due to its property to counteract the noise
sensitivity of the simple gradient operator. In order to achieve real-
time performance, a parallel architecture is designed, which uses three
processing elements to compute edge maps of R, G, and B color components.
The architecture is codedusing VHDL, simulated in ModelSim, synthesized
using Xilinx ISE 10.1 and implemented on Xilinx ML510 (Virtex-5 FX130T)
FPGA platform. The complete system is working at 27 MHz clock frequency.
The measured performance of our system for standard PAL (720x576) size
images is 50 fps (frames per second) and CIF (352x288) size images is
200 fps.
Index Terms— Real-time Color Image Edge Detection, Sobel Operator,
FPGA Implementation, VLSI Architecture, Color Edge Detection Processor
I. INTRODUCTION
High speed industrial applications require very accurate and real-
time edge detection. Edge detection in gray images does not give very
accurate results due to loss of color information during color to gray
scale image conversion. Therefore, to achieve desired accuracy,
detection of edges in color images is necessary. The main challenge for
real-time implementation of color image edge detection is in processing
of high volume of data (3 times as compared to gray images) within real-
time constraints. Therefore, it is hard to achieve real-time performance
of edge detection for PAL sizes color images with serial processors. Due
to inherent parallelism property, FPGAs can deliver real-time time
performance for such applications. Furthermore, FPGAs provide the
possibility to perform algorithm modifications in later stages of the
system development [1].
The main focus of most of the existing FPGA based implementations
for edge detection using Sobel operator has been on achieving real-time
performance for gray scale images by using various architectures and
different design methodologies. As edge detection is low-level image
processing operation, Single Instruction Multiple Data (SIMD) type
architectures [2] are very suitable for edge detection to achieve real-
time performance. These architectures use multiple data processing
elements and therefore, require more FPGA resources. The architecture
clock
frequency can be improved by using pipelining. A pipelined
architecture for real-time gray image edge detection is presented in [3].
Some computation optimized architectures are presented in [4, 5]. Few
more architectures for real-time gray image edge detection are available
in [6 - 11]. In [12, 13], the architectures are designed using MATLAB-
Simulink based design methodology.
In this paper, we show that real-time Sobel operator based color
image edge detection can be achieved by using a FPGA based parallel
architecture. For each color component in RGB space, one specific edge
computation processor is developed. As Sobel operator is sliding window
operator, smart buffer based Memory architecture is used to move the
incoming pixels in computing window. The specific datapaths are designed
and controller is developed to perform the complete task. The design and
simulation is done using VHDL. The design is targeted to Xilinx ML 510
(Virtex–5 FX130T) FPGA platform. The implementation is tested for real
world
scenario. It can robustly detect the edges in color images.
The rest of the paper is organized in the following way. In section
2 we describe the original Sobel operator based edge detection algorithm.
We show, in section 3, the customized architecture for algorithm
implementation and how each stage works. In section 4, practical tests
are evaluated and synthesis results are shown taking into account system
performance. Finally conclusions and
discussions are presented in section 5.
II. EDGE DETECTION SCHEME
In this section the used algorithm is briefly described, for a more
detailed description we refer to [14, 15]. The Sobel operator is widely
used for edge detection in images. It is based on computing an
approximation of thegradient of the image intensity function. The Sobel
filter uses two 3x3 spatial masks which are convolved with the original
image to calculate the approximations of the
gradient. The Sobel operator uses two filters Hx and Hy.
,101,,
,,H,,202 (1) X,,
,,,101,,
-1-2-1,,
,,H,001 (2) y,,
,,121,,
These filters compute the gradient components across the neighboring
lines or columns, respectively. The smoothing is performed over three
lines or columns before computing the respective gradients. In this
Sobel operator, the higher weights are assigned in smoothing part to
current center line and column as compared to simple gradient operators.
The local edge strength is defined as the gradient magnitude given by
equation 3.
22,,GMx,y,Hx,Hy (3)
This equation 3 is computationally costly because of square and
square root operations for every pixel. It is more suitable
computationally to approximate the square and square root operations by
absolute values.
,,GMx,y,Hx,Hy (4)
This expression is much easy to compute and still preserves the
relative changes in intensity (edges in images).
This above mentioned scheme is for gray scale images. For color
images (RGB color space) this scheme is applied separately for each
color component. Final color edge map of color image is computed by
using the edge maps of each color component [16].
(5) ColorEdge,(EdgeRorEdgeGorEdgeB)
III. PROPOSED ARCHITECTURE
To detect edges in real-time in PAL (720x576) size color images,
dedicated hardware architecture is implemented for Sobel operator based
edge detection scheme. Fig. 1 shows the conceptual block diagram of
complete system. The hardware setup includes a video camera, a video
daughter card, and FPGA board. The video output of camera connects to
Digilent VDEC1 Video Decoder Board which is interfaced with Xilinx ML510
(Virtex–5 FX130T) board using
Interface PCB. Display Monitor is connected to the board using DVI
connector. The video signals are decoded in Camera Interface Module. The
output RGB data of camera interface module is applied to edge detection
block. The edge detected output from the Edge Detection Block is
displayed on the display monitor using DVI controller. The camera
interface module also generates video timing signals which are necessary
剩余30页未读,继续阅读
资源评论
若♡
- 粉丝: 6194
- 资源: 1万+
上传资源 快速赚钱
- 我的内容管理 展开
- 我的资源 快来上传第一个资源
- 我的收益 登录查看自己的收益
- 我的积分 登录查看自己的积分
- 我的C币 登录后查看C币余额
- 我的收藏
- 我的下载
- 下载帮助
安全验证
文档复制为VIP权益,开通VIP直接复制
信息提交成功