In this work we propose a new formulation for hyperspectral denoising based on the Blind Compressed Sensing (BCS) framework. BCS learns the sparsifying basis during signal recovery combining the advantages of standard...
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ISBN:
(纸本)9781467385640
In this work we propose a new formulation for hyperspectral denoising based on the Blind Compressed Sensing (BCS) framework. BCS learns the sparsifying basis during signal recovery combining the advantages of standard sparse recovery with dictionary learning. We show that our proposed formulation yields better results than a state-of-the-art technique hyperspectral denoising both in terms of PSNR (more than 1dB improvement) and visual quality.
This paper presents a camera model to deal with underwater scene reconstruction from multiple images. Effects due to change in path of light ray at the medium interface is modelled for a general medium with unknown re...
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ISBN:
(纸本)9781467385640
This paper presents a camera model to deal with underwater scene reconstruction from multiple images. Effects due to change in path of light ray at the medium interface is modelled for a general medium with unknown refractive index. Our model calculates the refractive index of the medium and simultaneously removes the geometric refraction effects in images using point correspondences in image pairs. With known internal parameters of the camera we find the external parameters of the camera and then 3-D reconstruction is obtained.
We have developed a novel method for image abstraction which preserves more details present in the salient regions and removes details present in the non- salient regions from the given image of a natural scene. We de...
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ISBN:
(纸本)9781467385640
We have developed a novel method for image abstraction which preserves more details present in the salient regions and removes details present in the non- salient regions from the given image of a natural scene. We define a region to be salient based on the saliency measure estimated in the region. We propose to preserve details in salient regions by dividing them into smaller groups of pixels and remove details from non- salient regions by dividing them in larger group of pixels. We achieve this kind of grouping by guiding an over- segmentation algorithm with spatially varying block size depending on the saliency measure. The adaptive image abstraction goal is finally achieved using a novel brush called point spread brush which is used to reproduce the action of brush with a varying spatial spread.
We target the problem of image Denoising using Gaussian Processes Regression (GPR). Being a non- parametric regression technique, GPR has received much attention in the recent past and here we further explore its vers...
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ISBN:
(纸本)9781467385640
We target the problem of image Denoising using Gaussian Processes Regression (GPR). Being a non- parametric regression technique, GPR has received much attention in the recent past and here we further explore its versatility by applying it to a denoising problem. The focus is primarily on the design of a local gradient sensitive kernel that captures pixel similarity in the context of image denoising. This novel kernel formulation is used to shape the smoothness of the joint GP prior. We apply the GPR denoising technique to small patches and then stitch back these patches, this allows the priors to be local and relevant, also this helps us in dealing with GPR complexity. We demonstrate that our GPR based technique gives better PSNR values in comparison to existing popular denoising techniques.
In this paper, a view invariant watermarking scheme is proposed for depth image 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 depth image 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.
Accurate detection of optic disk and macula are of interest in automated analysis of retinal images as they are landmarks in retina and their detection aids in assessing the severity of diseases based on the locations...
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ISBN:
(纸本)9781467385640
Accurate detection of optic disk and macula are of interest in automated analysis of retinal images as they are landmarks in retina and their detection aids in assessing the severity of diseases based on the locations of abnormalities relative to these landmarks. The general strategy is to design different methods to these landmarks. In contrast, we propose a novel and unified approach for Optic disk and macula detection in this paper using the Generalized Motion Pattern (GMP) [10] [19] which is derived by inducing motion to an image to smooth out unwanted information. The proposed method is unsupervised, parallelizable and handles illumination differences efficiently but assumes a fixed protocol in image acquisition. The proposed method has been tested on five public datasets and obtained results indicate comparable performance to supervised approaches for the same problem.
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.
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.
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