In this paper, a view invariant watermarking scheme is proposed for depthimage based rendering (DIBR) 3D image representation. To make the scheme invariant against view synthesis process, the watermark is inserted in...
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ISBN:
(纸本)9781467385640
In this paper, a view invariant watermarking scheme is proposed for depthimage based rendering (DIBR) 3D image representation. To make the scheme invariant against view synthesis process, the watermark is inserted in the image locations selected by the SIFT (Scale-invariant feature transform) feature points. A novel SIFT feature based coefficient selection scheme has been implemented for watermark embedding by exploiting the shift invariance and directional property of the DIBR based view synthesis process. A coefficient partitioning based blind watermarking method has been included to make the scheme more efficient. A comprehensive set of experiments have been carried out to justify the robustness of the proposed scheme against the view synthesis attack.
image retrieval techniques finds very useful in content management systems. Content Based image Retrieval (CBIR) methods incorporates specific image features such as colors, textures, keypoints etc., for retrieving si...
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ISBN:
(纸本)9781467385640
image retrieval techniques finds very useful in content management systems. Content Based image Retrieval (CBIR) methods incorporates specific image features such as colors, textures, keypoints etc., for retrieving similar images from databases. Most of the keypoint detectors and keypoint descriptors uses only grayscale information. the retrieval accuracy of these methods can be improved by adding additional color information to the keypoint descriptors. In this paper, an enhanced SURF descriptor is proposed for CBIR applications, which extracts the image features by computing the Hu moments along with eigen values in the immediate neighbourhood of the detected keypoints. Experimental results shows better image retrieval accuracy by using enhanced SURF descriptor. Also, the enhanced SURF descriptor is able to differentiate between images of same object having similar grayscale properties but having different colors.
Microaneurysms are small red dots that occur on the retina during preliminary stage of Diabetic Retinopathy. computer aided microaneurysm screening is necessary to prevent the aggravation of the disease and further vi...
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ISBN:
(纸本)9781467385640
Microaneurysms are small red dots that occur on the retina during preliminary stage of Diabetic Retinopathy. computer aided microaneurysm screening is necessary to prevent the aggravation of the disease and further vision loss. In this paper, Shannon and Tsallis entropy thresholding in conjunction with Naive Bayes classifier is suggested for microaneurysm detection. Various shape and intensity based features are extracted to eliminate the falsely detected candidates. the proposed method is evaluated by plotting the FROC curves using the Retinopathy Online Challenge (ROC) and DIARETDB1 databases. the proposed method achieves high sensitivity values of 0.421 and 0.477 (at false positive rate of 8) using Shannon and Tsallis entropy thresholding which is better than some existing methods.
In recent times, there has been a sharp increase in dengue and malaria, especially in urban areas. One of the major reasons for this health hazard is the number of locations where one can find stagnant water. these lo...
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ISBN:
(纸本)9781467385640
In recent times, there has been a sharp increase in dengue and malaria, especially in urban areas. One of the major reasons for this health hazard is the number of locations where one can find stagnant water. these locations are large breeding ground for fast multiplying mosquitoes, and other insects. Areas include traditionally uncovered gutters, and also terraces of high rise buildings, and shades above windows (popularly known as chhajja)-areas that are hard to reach and access. In this paper we propose the use of a quadcopter to inspect such areas and identify stagnant water patches. Water being specular in nature tends to confound traditional imageprocessing methods. Further the use of a non-traditional camera mounted on a quadcopter presents new challenges. We provide methods to get past such hurdles.
image dehazing either using single visible image or using visible and near-infrared (NIR) image pair has seen growing interest in last decade for improving visibility in landscape photographs. In this paper, we propos...
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ISBN:
(纸本)9781467385640
image dehazing either using single visible image or using visible and near-infrared (NIR) image pair has seen growing interest in last decade for improving visibility in landscape photographs. In this paper, we propose a novel approach for image dehazing scheme using a pair of visible and NIR images. the dehazing mechanism estimates depth map and airlight color using the visible-NIR scene statistics and uses them to form a haze-free image. Experiments on a variety of hazy images demonstrate that our method achieves high degree of detail recovery over the existing image dehazing algorithms. the resultant images exhibit a very good blend of details, contrast and color. the proposed algorithm is less computationally demanding and is fully automatic. the results are superior in both visual as well as quantitative analysis compared to state-of-the-art image dehazing algorithms.
Background subtraction is an important preprocessing technique for a wide variety of problems in computervision including automatic video surveillance, anomaly detection etc. Our focus is on background subtraction of...
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ISBN:
(纸本)9781467385640
Background subtraction is an important preprocessing technique for a wide variety of problems in computervision including automatic video surveillance, anomaly detection etc. Our focus is on background subtraction of videos taken from stationary cameras. We use sparse representation and compressive sensing to propose a novel algorithm that separate the background image and present the foreground objects in each frame. Our method is robust to dynamic background scenario where the background changes with time. We also point towards the fact that our algorithm is highly parallalizable and so can subtract background in real time. We demonstrate the superiority of our method against Mixture of Gaussian, KDE model and Monnnet's method. Also our method is on par with AdaDGS in terms of visual result.
this paper presents a system for unconstrained handwritten Odia text recognition using Hidden Markov Model (HMM) framework. Existing literature for Odia text recognition works primarily with individual isolated charac...
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ISBN:
(纸本)9781467385640
this paper presents a system for unconstrained handwritten Odia text recognition using Hidden Markov Model (HMM) framework. Existing literature for Odia text recognition works primarily with individual isolated characters. In this study we introduce a Odia dataset of word samples collected from different professionals. Concavity feature from each word image is extracted in our approach. Next, the features are fed to HMM-based sequential classifier for recognition. the experiment has been performed on a large dataset consisting of 4000 words and results obtained are encouraging.
the main objective of this paper aims at designing an efficient blind assistance system for the visually impaired people using real time disparity estimation algorithm. the local window based matching algorithms known...
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the main objective of this paper aims at designing an efficient blind assistance system for the visually impaired people using real time disparity estimation algorithm. the local window based matching algorithms known as sum of absolute differences (SAD) and zero-mean SAD (ZSAD) are used for the disparity estimation and efficient hardware architectures for those algorithms are implemented in FPGA. the SAD and ZSAD algorithms are implemented for the image resolution of 640x360 pixels with square window of size 8x8 pixels and with a disparity range of 0 to 99. An efficient line buffering scheme for the left and right window of the two camera images is implemented to support the parallel processing mechanism. To provide high frame rate per second (fps) to the artificial vision system, parallel processing architecture for disparity estimation is required, but it consumes huge amount of hardware resources which is not desirable for this application. So, semi-parallel architectures are implemented for SAD and ZSAD algorithms for a compromise between hardware resource utilization and speed. the FPGA resource utilization for the ZSAD and SAD algorithms for a frame rate of 30 fps are 43529 LUTs, 50144 FFs and 34548 LUTs, 37544 FFs respectively. ZSAD algorithm consumes around 30% more hardware resources compared to SAD, but to counter the randomized distortion caused by the non-ideal stereo cameras ZSAD is more preferred. Finally from the disparity, the distance of the nearest obstacle is estimated and blind person is alerted through audio device instructions.
In the present work, we propose a framework for retrieving metric information of featureless cylindrical pellet imaged through stereo vision. Considering the isometry property, relative affine structure which is an in...
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ISBN:
(纸本)9781467385640
In the present work, we propose a framework for retrieving metric information of featureless cylindrical pellet imaged through stereo vision. Considering the isometry property, relative affine structure which is an invariant that depends on the depth of the point is employed for obtaining the information. this method skips considering vanishing points for depth estimation, and hence the errors are reduced remarkably as no points are assumed to be at infinity. Real world measurements are taken and the metrics of a selected reference point is assumed to be known. Withthese minimal information the mapping between the images using the relative affine structure is carried out that enables the 3D reconstruction. this work also blends the concepts of 360 degree rotational symmetry and orthogonal planes withthe stereo visionthat has minimized the error percentage. the results presented by the theory will have an impact on the design of 3D reconstruction systems for computervision and its applications.
Wavelet transform of the image generates the different components basically classified in the approximation and detail components. the approximation component has major information. In this paper a partial encryption ...
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ISBN:
(纸本)9781467385640
Wavelet transform of the image generates the different components basically classified in the approximation and detail components. the approximation component has major information. In this paper a partial encryption technique is used, using only approximation component. In this paper a random array is generated which is XORed withthe approximation component. the inverse transform of the matrix generated by this operation generates the encrypted image. the random array, the wavelet used and level of wavelet transform jointly serves as the key for the decryption process. In decryption is just reverse of the encryption steps.
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