The field of computer vision has become an important part of today's society, supporting crucial applications in the medical, manufacturing, military intelligence and surveillance domains. Many computer vision tasks can be divided into fundamental steps: image acquisition, pre-processing, feature extraction, detection or segmentation, and high-level processing. This work focuses on classification and object detection, specifically k-Nearest Neighbors, Support Vector Machine classification, and Viola & Jones object detection. Object detection and classification algorithms are computationally intensive, which makes it difficult to perform classification tasks in real-time. This thesis aims in overcoming the processing limitations of the above classification algorithms by offloading computation to the graphics processing unit (GPU) using NVIDIA's Compute Unified Device Architecture (CUDA). The primary focus of this work is the implementation of the Viola and Jones object detector in CUDA. A multi-GPU implementation provides a speedup ranging from 1x to 6.5x over optimized OpenCV code for image sizes of 300 x 300 pixels up to 2900 x 1600 pixels while having comparable detection results. The second part of this thesis is the implementation of a multi-GPU multi-class SVM classifier. The classifier had the same accuracy as an identical implementation using LIBSVM with a speedup ranging from 89x to 263x on the tested datasets. The final part of this thesis was the extension of a previous CUDA k-Nearest Neighbor implementation by exploiting additional levels of parallelism. These extensions provided a speedup of 1.24x and 2.35x over the previous CUDA implementation. As an end result of this work, a library of these three CUDA classifiers has been compiled for use by future researchers.
Library of Congress Subject Headings
Computer vision; Classification--Data processing; Computer algorithms
Department, Program, or Center
Computer Engineering (KGCOE)
Harvey, Jesse Patrick, "GPU acceleration of object classification algorithms using NVIDIA CUDA" (2009). Thesis. Rochester Institute of Technology. Accessed from
RIT – Main Campus