Computer Vision,Imaging and Computer Graphics

Vision-Realistic Rendering: Simulation of the Scanned Foveal Image with Elimination of Artifacts due to Occlusion and Discretization (Computer Vision,Imaging and Computer Graphics) Part 1

Abstract. We introduce the concept of vision-realistic rendering – the computer generation of synthetic images that incorporate the characteristics of a particular individual’s entire optical system. Specifically, this paper develops a method for simulating the scanned foveal image from wavefront data of actual human subjects, and demonstrates those methods on sample images. First, a subject’s […]

Vision-Realistic Rendering: Simulation of the Scanned Foveal Image with Elimination of Artifacts due to Occlusion and Discretization (Computer Vision,Imaging and Computer Graphics) Part 2

Algorithm Figure 2 provides an overview of the vision-realistic rendering algorithm, comprising three major components. Constructing the Object Space Point Spread Function A Point Spread Function (PSF) plots the distribution of light energy on the image plane based on light that has emanated from a point source and has passed through an optical system. Thus […]

Vision-Realistic Rendering: Simulation of the Scanned Foveal Image with Elimination of Artifacts due to Occlusion and Discretization (Computer Vision,Imaging and Computer Graphics) Part 3

Elimination of Artifacts Due to Occlusion and Discretization Although processing in image space allows an increase in speed, the images may have artifacts introduced. This can occur in two ways, which we refer to as occlusion and discretization [7] [8]. The occlusion problem arises because there is scene geometry that is missing. This results from […]

Vision-Realistic Rendering: Simulation of the Scanned Foveal Image with Elimination of Artifacts due to Occlusion and Discretization (Computer Vision,Imaging and Computer Graphics) Part 4

Sample Images Figures 1, 19, 20, and 21 are vision-realistic renderings of a room scene. Figure 18 is a simulation that models ideal vision and Figures 1, 19, 20, and 21 are simulations of the vision of actual individuals based on their measured data. Notice that the nature of the blur is different in each […]

Fisher Vectors: Beyond Bag-of-Visual-Words Image Representations (Computer Vision,Imaging and Computer Graphics) Part 1

Abstract. The Fisher Vector (FV) representation of images can be seen as an extension of the popular bag-of-visual word (BOV). Both of them are based on an intermediate representation, the visual vocabulary built in the low level feature space. If a probability density function (in our case a Gaussian Mixture Model) is used to model […]

Fisher Vectors: Beyond Bag-of-Visual-Words Image Representations (Computer Vision,Imaging and Computer Graphics) Part 2

Image Categorization with FV Figure 2 illustrated the schema of our Generic Visual Categorization system. In which follows we present the results of several categorization experiments with this system using FVs. In all the experiments we used as low level features either SIFT-like Orientation Histograms (ORH) alone or in combination with local RGB statistics (COL). […]

Decoding 1-D Barcode from Degraded Images Using a Neural Network (Computer Vision,Imaging and Computer Graphics) Part 1

Abstract. Today we know that billions of products carry the 1-D bar codes, and with the increasing availability of camera phones, many applications that take advantage of immediate identification of the barcode are possible. The existing open-source libraries for 1-D barcodes recognition are not able to recognize the codes from images acquired using simple devices […]

Decoding 1-D Barcode from Degraded Images Using a Neural Network (Computer Vision,Imaging and Computer Graphics) Part 2

Experiments The performance of ZXing-MOD was evaluated and compared with the original ZXing and with other two open-source libraries: BaToo5 and JJil6. System performances are compared using precision P and recall R [27], where correct is the number of barcodes correctly recognized by the system, actual is the total number of barcodes recognized by the […]

Perspective Two-Frame-Theory for Shape Recovery under Turntable Motion (Computer Vision,Imaging and Computer Graphics) Part 1

Abstract. This paper addresses the problem of shape from shadings under perspective projection and turntable motion.Two-Frame-Theory is a newly proposed method for 3D shape recovery. It estimates shape by solving a first order quasi-linear partial differential equation through the method of characteristics. One major drawback of this method is that it assumes an orthographic camera […]

Perspective Two-Frame-Theory for Shape Recovery under Turntable Motion (Computer Vision,Imaging and Computer Graphics) Part 2

Experiments The proposed method is tested on synthetic models and real image sequence. The camera and light source are fixed and fully calibrated. Circular motion sequences are captured either through simulation or by rotating the object on a turntable for all experiments. Since the derived first order quasi-linear partial differential equation is based on the […]

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