Detection and segmentation of defocus blur is a challenging task in digital imaging applications as the blurry images comprise of blur and sharp regions that wrap significant information and require effective methods ...Detection and segmentation of defocus blur is a challenging task in digital imaging applications as the blurry images comprise of blur and sharp regions that wrap significant information and require effective methods for information extraction.Existing defocus blur detection and segmentation methods have several limitations i.e.,discriminating sharp smooth and blurred smooth regions,low recognition rate in noisy images,and high computational cost without having any prior knowledge of images i.e.,blur degree and camera configuration.Hence,there exists a dire need to develop an effective method for defocus blur detection,and segmentation robust to the above-mentioned limitations.This paper presents a novel features descriptor local directional mean patterns(LDMP)for defocus blur detection and employ KNN matting over the detected LDMP-Trimap for the robust segmentation of sharp and blur regions.We argue/hypothesize that most of the image fields located in blurry regions have significantly less specific local patterns than those in the sharp regions,therefore,proposed LDMP features descriptor should reliably detect the defocus blurred regions.The fusion of LDMP features with KNN matting provides superior performance in terms of obtaining high-quality segmented regions in the image.Additionally,the proposed LDMP features descriptor is robust to noise and successfully detects defocus blur in high-dense noisy images.Experimental results on Shi and Zhao datasets demonstrate the effectiveness of the proposed method in terms of defocus blur detection.Evaluation and comparative analysis signify that our method achieves superior segmentation performance and low computational cost of 15 seconds.展开更多
目的散焦模糊检测致力于区分图像中的清晰与模糊像素,广泛应用于诸多领域,是计算机视觉中的重要研究方向。待检测图像含复杂场景时,现有的散焦模糊检测方法存在精度不够高、检测结果边界不完整等问题。本文提出一种由粗到精的多尺度散...目的散焦模糊检测致力于区分图像中的清晰与模糊像素,广泛应用于诸多领域,是计算机视觉中的重要研究方向。待检测图像含复杂场景时,现有的散焦模糊检测方法存在精度不够高、检测结果边界不完整等问题。本文提出一种由粗到精的多尺度散焦模糊检测网络,通过融合不同尺度下图像的多层卷积特征提高散焦模糊的检测精度。方法将图像缩放至不同尺度,使用卷积神经网络从每个尺度下的图像中提取多层卷积特征,并使用卷积层融合不同尺度图像对应层的特征;使用卷积长短时记忆(convolutional long-short term memory,Conv-LSTM)层自顶向下地整合不同尺度的模糊特征,同时生成对应尺度的模糊检测图,以这种方式将深层的语义信息逐步传递至浅层网络;在此过程中,将深浅层特征联合,利用浅层特征细化深一层的模糊检测结果;使用卷积层将多尺度检测结果融合得到最终结果。本文在网络训练过程中使用了多层监督策略确保每个Conv-LSTM层都能达到最优。结果在DUT(Dalian University of Technology)和CUHK(The Chinese University of Hong Kong)两个公共的模糊检测数据集上进行训练和测试,对比了包括当前最好的模糊检测算法BTBCRL(bottom-top-bottom network with cascaded defocus blur detection map residual learning),De Fusion Net(defocus blur detection network via recurrently fusing and refining multi-scale deep features)和DHDE(multi-scale deep and hand-crafted features for defocus estimation)等10种算法。实验结果表明:在DUT数据集上,本文模型相比于De Fusion Net模型,MAE(mean absolute error)值降低了38.8%,F0.3值提高了5.4%;在CUHK数据集上,相比于LBP(local binary pattern)算法,MAE值降低了36.7%,F0.3值提高了9.7%。通过实验对比,充分验证了本文提出的散焦模糊检测模型的有效性。结论本文提出的由粗到精的多尺度散焦模糊检测方法,通过融合不同尺度图像的特征,以展开更多
基金This work was supported and funded by the Directorate ASR&TD of UET-Taxila.
文摘Detection and segmentation of defocus blur is a challenging task in digital imaging applications as the blurry images comprise of blur and sharp regions that wrap significant information and require effective methods for information extraction.Existing defocus blur detection and segmentation methods have several limitations i.e.,discriminating sharp smooth and blurred smooth regions,low recognition rate in noisy images,and high computational cost without having any prior knowledge of images i.e.,blur degree and camera configuration.Hence,there exists a dire need to develop an effective method for defocus blur detection,and segmentation robust to the above-mentioned limitations.This paper presents a novel features descriptor local directional mean patterns(LDMP)for defocus blur detection and employ KNN matting over the detected LDMP-Trimap for the robust segmentation of sharp and blur regions.We argue/hypothesize that most of the image fields located in blurry regions have significantly less specific local patterns than those in the sharp regions,therefore,proposed LDMP features descriptor should reliably detect the defocus blurred regions.The fusion of LDMP features with KNN matting provides superior performance in terms of obtaining high-quality segmented regions in the image.Additionally,the proposed LDMP features descriptor is robust to noise and successfully detects defocus blur in high-dense noisy images.Experimental results on Shi and Zhao datasets demonstrate the effectiveness of the proposed method in terms of defocus blur detection.Evaluation and comparative analysis signify that our method achieves superior segmentation performance and low computational cost of 15 seconds.
文摘目的散焦模糊检测致力于区分图像中的清晰与模糊像素,广泛应用于诸多领域,是计算机视觉中的重要研究方向。待检测图像含复杂场景时,现有的散焦模糊检测方法存在精度不够高、检测结果边界不完整等问题。本文提出一种由粗到精的多尺度散焦模糊检测网络,通过融合不同尺度下图像的多层卷积特征提高散焦模糊的检测精度。方法将图像缩放至不同尺度,使用卷积神经网络从每个尺度下的图像中提取多层卷积特征,并使用卷积层融合不同尺度图像对应层的特征;使用卷积长短时记忆(convolutional long-short term memory,Conv-LSTM)层自顶向下地整合不同尺度的模糊特征,同时生成对应尺度的模糊检测图,以这种方式将深层的语义信息逐步传递至浅层网络;在此过程中,将深浅层特征联合,利用浅层特征细化深一层的模糊检测结果;使用卷积层将多尺度检测结果融合得到最终结果。本文在网络训练过程中使用了多层监督策略确保每个Conv-LSTM层都能达到最优。结果在DUT(Dalian University of Technology)和CUHK(The Chinese University of Hong Kong)两个公共的模糊检测数据集上进行训练和测试,对比了包括当前最好的模糊检测算法BTBCRL(bottom-top-bottom network with cascaded defocus blur detection map residual learning),De Fusion Net(defocus blur detection network via recurrently fusing and refining multi-scale deep features)和DHDE(multi-scale deep and hand-crafted features for defocus estimation)等10种算法。实验结果表明:在DUT数据集上,本文模型相比于De Fusion Net模型,MAE(mean absolute error)值降低了38.8%,F0.3值提高了5.4%;在CUHK数据集上,相比于LBP(local binary pattern)算法,MAE值降低了36.7%,F0.3值提高了9.7%。通过实验对比,充分验证了本文提出的散焦模糊检测模型的有效性。结论本文提出的由粗到精的多尺度散焦模糊检测方法,通过融合不同尺度图像的特征,以
