Abstract:Optical navigation (OPNAV) is the use of the on-board imaging data to provide a direct measurement of the image coordinates of the target as navigation information. Among the optical observables in deep-space, the edge of the celestial body is an important feature that can be utilized for locating the planet centroid. However, traditional edge detection algorithms like Canny algorithm cannot be applied directly for OPNAV due to the noise edges caused by surface markings. Moreover, due to the constrained comput… Show more
“…The input image is preprocessed by convolution filter with Gaussian filter to remove noise and reduce the influence of noise on gradient calculation, so as to better realize the effect of edge detection image segmentation. Therefore, image preprocessing requires convolution of the original image and Gaussian mask, and the processed image is more blurred than the original, which is conducive to image edge detection [36].…”
In the process of Canny edge detection, a large number of high complexity calculations such as Gaussian filtering, gradient calculation, non-maximum suppression, and double threshold judgment need to be performed on the image, which takes up a lot of operation time, which is a great challenge to the real-time requirements of the algorithm. The traditional Canny edge detection technology mainly uses customized equipment such as DSP and FPGA, but it has some problems, such as long development cycle, difficult debugging, resource consumption, and so on. At the same time, the adopted CUDA platform has the problem of poor cross-platform. In order to solve this problem, a fine-grained parallel Canny edge detection method is proposed, which is optimized from three aspects: task partition, vector memory access, and NDRange optimization, and CPU-GPU collaborative parallelism is realized. At the same time, the parallel Canny edge detection methods based on multi-core CPU and CUDA architecture are designed. The experimental results show that OpenCL accelerated Canny edge detection algorithm (OCL_Canny) achieves 20.68 times acceleration ratio compared with CPU serial algorithm at 7452 × 8024 image resolution. At the image resolution of 3500 × 3500, the OCL_Canny algorithm achieves 3.96 times the acceleration ratio compared with the CPU multi-threaded Canny parallel algorithm. At 1024 × 1024 image resolution, the OCL_Canny algorithm achieves 1.21 times the acceleration ratio compared with the CUDA-based Canny parallel algorithm. The effectiveness and performance portability of the proposed Canny edge detection parallel algorithm are verified, and it provides a reference for the research of fast calculation of image big data.
“…The input image is preprocessed by convolution filter with Gaussian filter to remove noise and reduce the influence of noise on gradient calculation, so as to better realize the effect of edge detection image segmentation. Therefore, image preprocessing requires convolution of the original image and Gaussian mask, and the processed image is more blurred than the original, which is conducive to image edge detection [36].…”
In the process of Canny edge detection, a large number of high complexity calculations such as Gaussian filtering, gradient calculation, non-maximum suppression, and double threshold judgment need to be performed on the image, which takes up a lot of operation time, which is a great challenge to the real-time requirements of the algorithm. The traditional Canny edge detection technology mainly uses customized equipment such as DSP and FPGA, but it has some problems, such as long development cycle, difficult debugging, resource consumption, and so on. At the same time, the adopted CUDA platform has the problem of poor cross-platform. In order to solve this problem, a fine-grained parallel Canny edge detection method is proposed, which is optimized from three aspects: task partition, vector memory access, and NDRange optimization, and CPU-GPU collaborative parallelism is realized. At the same time, the parallel Canny edge detection methods based on multi-core CPU and CUDA architecture are designed. The experimental results show that OpenCL accelerated Canny edge detection algorithm (OCL_Canny) achieves 20.68 times acceleration ratio compared with CPU serial algorithm at 7452 × 8024 image resolution. At the image resolution of 3500 × 3500, the OCL_Canny algorithm achieves 3.96 times the acceleration ratio compared with the CPU multi-threaded Canny parallel algorithm. At 1024 × 1024 image resolution, the OCL_Canny algorithm achieves 1.21 times the acceleration ratio compared with the CUDA-based Canny parallel algorithm. The effectiveness and performance portability of the proposed Canny edge detection parallel algorithm are verified, and it provides a reference for the research of fast calculation of image big data.
“…Therefore, image preprocessing requires convolution of the original image and Gaussian mask, and the processed image is more blurred than the original, which is conducive to image edge detection [35].…”
In the process of Canny edge detection, a large number of high complexity calculations such as Gaussian filtering, gradient calculation, non-maximum suppression, and double threshold judgment need to be performed on the image, which takes up a lot of operation time, which is a great challenge to the real-time requirements of the algorithm. In order to solve this problem, a fine-grained parallel Canny edge detection method is proposed, which is optimized from three aspects: task partition, vector memory access, and NDRange optimization, and CPU-GPU collaborative parallelism is realized. At the same time, the parallel Canny edge detection methods based on multi-core CPU and CUDA architecture are designed. The experimental results show that OpenCL accelerated Canny edge detection algorithm can achieve 20.68 times, 3.96 times, and 1.21 times speedup ratio compared with CPU serial algorithm, CPU multi-threaded parallel algorithm, and CUDA-based parallel algorithm, respectively. The effectiveness and performance portability of the proposed Canny edge detection parallel algorithm are verified, and it provides a reference for the research of fast calculation of image big data.
“…Compared with input learning, output can stimulate students' desire and enthusiasm for learning, and achieve better learning efficiency. In other words, language teaching starts with an output task, and then students try their best to complete the output task [22]. In this process, students will not only realize the practical value of output tasks in improving cultural literacy and communicative competence, but also realize their own language skills insufficiency.…”
In the context of globalization, English, as a unique passport to the world, is an important way for countries to communicate in information, technology, and culture. The output-oriented approach is a new theory of foreign language learning and teaching constructed by Chinese scholars, which has attracted widespread attention from foreign language scholars and front-line teachers and is expected to address the issue of “separation of learning and use” of English in Chinese universities. In the context of globalization, English, as a unique passport to the world, is an essential way for countries to exchange ideas about information, technology, and culture. Therefore, there is no doubt that English education plays a crucial role in nurturing the younger generation, especially at the high school level. This paper introduces an edge detection algorithm and an output-oriented approach to the teaching model of English translation. Questionnaires were administered to students in the control and experimental classes. The percentages of students who strongly disagreed, disagreed, neutral, agreed, and strongly agreed with the translation task based on their interest were 1.9%, 13%, 25.1%, 36.8%, and 23.2%, respectively.
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