Stereoscopic ray tracing on graphics processors

Download
2012
Daş, Alper
Stereoscopic rendering methods generate two images for binocular viewing. Exploiting the spatial coherence present in the surfaces rendered, it is possible to reduce the rendering time of a stereoscopic image pair significantly. Ray tracing is a frequently used rendering method for realistic image synthesis applications. With the tremendous increase in computational power of Graphics Processing Units and their availability for general purpose programming, ray tracing methods suitable for Graphics Processing Units have been developed. In this thesis, a parallel stereoscopic ray tracing method that reuses view independent information in one of the stereoscopic image pairs for generating the other image is presented. The results of the method are analyzed using a perception based error detection mechanism. The main contribution lies in the new parallel algorithm that takes advantage of the massive parallel processing power of the modern Graphics Processing Units efficiently. Results show that about 20 times speed-up is achieved overall previous work which is based on a sequential algorithm in the worst case among the experiments carried out. According to the perception based quality analysis performed, lower than only 2% of the pixels in high resolution images is expected to be perceived to be in error.

Suggestions

Multi-modal stereo-vision using infrared / visible camera pairs
Yaman, Mustafa; Kalkan, Sinan; Department of Computer Engineering (2014)
In this thesis, a novel method for computing disparity maps from a multi-modal stereo-vision system composed of an infrared-visible camera pair is introduced. The method uses mutual information as the basic similarity measure where a segmentation based adaptive windowing mechanism is proposed along with a novel mutual information computation surface for greatly enhancing the results. Besides, the method incorporates joint prior probabilities when computing the cost matrix in addition to negative mutual info...
Statistical Analysis and Directional Coding of Layer-based HDR Image Coding Residue
Feyiz, Kutan; Kamışlı, Fatih; Zerman, Emin; Valenzise, Giuseppe; Koz, Alper; Dufaux, Frederic (2017-10-18)
Existing methods for layer-based backward compatible high dynamic range (HDR) image and video coding mostly focus on the rate-distortion optimization of base layer while neglecting the encoding of the residue signal in the enhancement layer. Although some recent studies handle residue coding by designing function based fixed global mapping curves for 8-bit conversion and exploiting standard codecs on the resulting 8-bit images, they do not take the local characteristics of residue blocks into account. Inspi...
Hyperspectral Superpixel Extraction Using Boundary Updates Based on Optimal Spectral Similarity Metric
Çalışkan, Akın; Koz, Alper; Alatan, Abdullah Aydın (2015-07-31)
The high spectral resolution of hyperspectral images (HSI) requires a heavy processing load. Assigning each pixel to a group in the image, which is called superpixel, and processing the superpixels instead of the pixels is resorted as a means to overcome this challenge in the hyperspectral literature. In this paper, we propose an algorithm to segment a hyperspectral image into superpixels by means of iteratively updating the boundary pixels of superpixels. We first explore the optimal similarity metric for ...
Real time panoramic background subtraction on GPU
BÜYÜKSARAÇ, SERDAR; Akar, Gözde; Temizel, Alptekin (2016-05-19)
In this study, we propose a method for panoramic background subtraction by using Pan-Tilt cameras in real-time. The proposed method is based on parallelization of image registration, panorama generation and background subtraction operations to run on Graphics Processing Unit (GPU). Experiments results showed that GPU usage increases speed of the algorithm 33 times without considerable performance loss and makes working real-time possible.
Color Preserving HDR Fusion for Dynamic Scenes
Karadağ, Gökdeniz; Akyüz, Ahmet Oğuz (2012-06-01)
We present a novel algorithm to efficiently generate high quality high dynamic range (HDR) images. Our method is based on the idea of expanding the dynamic range of a reference image at granularity of tiles. In each tile, we use data from a single exposure, but different tiles can come from different exposures. We show that this approach is not only efficient and robust against camera and object movement, but also improves the color quality of the resulting HDR images. We compare our method against the comm...
Citation Formats
A. Daş, “Stereoscopic ray tracing on graphics processors,” M.S. - Master of Science, Middle East Technical University, 2012.