Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 20 of 41 for “"Discrete Cosine Transform (DCT)"”.
-
A robust digital image watermarking using repetition codes against common attacks
… watermarking scheme has been implemented using Discrete Cosine Transform (DCT). The idea of this scheme is to embed an encoded watermark using repetition code (3, 1) inside the cover image pixels based on Discrete Cosine Transform (DCT) embedding technique. The proposed methods have undergone …
-
Fast implementation of integer transforms in H.264/AVC video encoders
The Integer Discrete Cosine Transform (IDCT) and Hadamard transforms are adopted in the H.264/AVC standard encoder for the compression of residual video signals. Other video standards such as the H.261, H.262 and H.263 use Discrete Cosine Transform (DCT).
-
Automatic Optimization of DSP Algorithms
… code. Timings are compared, using fast Fourier transform (FFT), Walsh-Hadama transform (WHT), discrete cosine transform (DCT) and discrete sine transform (DST) as the benchmarks, to those obtained by highly optimized implementations including FFTW and the WHT package. The results of this …
-
Hybrid DWT-DCT algorithm for image and video compression applications
… image/video information. There are various transformation techniques used for data compression. Discrete Cosine Transform (DCT) and Discrete Wavelet Transform (DWT) are the most commonly used transformation. DCT has high energy compaction property and requires less computational resources. …
-
Medical Image Registration Using Artificial Neural Network
<p>Image registration is the transformation of different sets of images into one coordinate system in order to align and overlay multiple images. Image registration is used in many fields such as medical imaging, remote sensing, and computer vision. It is very important in medical research, where …
-
Character extraction from ancient Chinese stele using discrete cosine transform
<p>"The discrete cosine transform (DCT) was applied to locate Chinese characters in ink rubbings of ancient Chinese steles (stone slabs with inscribed characters) in order to extract the characters by creating a bounding box in the image reconstructed by the inverse DCT. This work is a …
-
Design and analysis of a high-rate acoustic link for underwater video transmission
… methods. An experimental system, based on discrete cosine transform (DCT) and Huffman entropy coding for image compression, and variable rate M-ary quadrature amplitude modulation (QAM) was implemented. Phase-coherent equalization is accomplished by joint operation of a decision feedback …
-
Estimation of channelized features in geological media using sparsity constraint
… The solution is constrained to be sparse in the transform domain and the dimension of the search space is effectively reduced to a low frequency subspace to improve estimation efficiency. The solution subspace is spanned by a subset of a discrete cosine transform (DCT) basis containing …
-
Assessing the benefits of DCT compressive sensing for computational electromagnetics
… applications. This algorithm is known as the discrete cosine transform (DCT) method. Using the DCT algorithm, I have developed a compressive sensing software implementation. Through the course of my research I have tested both the accuracy and runtime efficiency of this software implementation …
-
Astronomical image manipulation in the transform domain
… bandwidth. Among many image compression schemes, transform coding is a widely used coding method. Traditionally, processing a compressed image requires decompression first. Following manipulations, the processed image is compressed again for storage. To reduce the computational complexity and …
-
Ultrawideband Indoor Location And Tracking System
… targets in indoor locations. We also use Discrete Cosine Transform (DCT) to compress the UWB scan waveforms from the receivers to the main computer to conserve bandwidth. At the main computer, we use Inverse DCT to recover the original signal. The UWB intruder detection system has the …
-
Digital Hardware Architectures for Exact and Approximate DCT Computation Using Number Theoretic Techniques
The discrete cosine transform (DCT) is a key tool in many image and video coding applications. Therefore significant effort is been made to realize DCT computation utilizing minimum resources in terms of hardware, at acceptable accuracy. This thesis explores the use of number theoretic techniques …
-
A study of probability distributions of DCT coefficients in JPEG compression
The Discrete Cosine Transform (DCT) used in JPEG compression has shown excellent energy compaction properties that rival that of the ideal Karhunen-Loeve Transform. Lossy compression in JPEG is achieved by distorting 8x8 block DCT coefficients through quantization. It has been shown in literature …
-
Soft N-modular redundancy: exploiting statistics for robust computation
… in the design of an energy-e cient and robust discrete cosine transform (DCT) image coder. Simulations in a commercial 45 nm, 1:2 V, CMOS process show that soft triple-MR (TMR) provides 10 improvement in robustness and 13% power savings over TMR at the same peak signal-to-noise ratio (PSNR) of …
-
A comparison of discrete cosine transform and discrete wavelet transform algorithm in watermarking against common attacks
… there is no comparison documented done between Discrete Cosine Transform (DCT) and Discrete Wavelet Transform (DWT). In this report, the DCT watermarking algorithms and DWT watermarking algorithms were compared based on robustness and imperceptibility criteria. With DCT, the watermark bits were …
-
Design and evaluation of a data-dependent low-power 8x8 DCT/IDCT
Traditional fast Discrete Cosine Transform (DCT)/ Inverse DCT (IDCT) algorithms have focused on reducing arithmetic complexity and have fixed run-time complexities regardless of the input. Recently, data-dependent signal processing has been applied to the DCT/IDCT. These algorithms have variable …
-
Hardware implementation of a low-power two-dimensional discrete cosine transform
… compliant, low-power dedicated, two-dimensional, Discrete Cosine Transform (DCT) core meeting all IBM Softcore requirements is developed. Power is optimized completely at the algorithmic, architectural, and logic levels. The architecture uses row-column decomposition of a fast 1-D algorithm …
-
Transforms for prediction residuals in video coding
Typically the same transform, the 2-D Discrete Cosine Transform (DCT), is used to compress both image intensities in image coding and prediction residuals in video coding. Major prediction residuals include the motion compensated prediction residual, the resolution enhancement residual in scalable …
-
On the Low Power Design of DCT and IDCT for Low Bit Rate Video Codecs
… intensive operations in H.263 are the Discrete Cosine Transform (DCT) and the Inverse Discrete Cosine Transform (IDCT), which perform spatial compression and decompression of the data. In an ASIC implementation of H.263, the high computational complexity of the DCT and IDCT leads to …
-
Source coded image data in the presence of channel errors
… of images with the emphasis almost totally on transform coding. The transform technique adopted is the Discrete Cosine Transform (DCT) which becomes common to both transform coders. Hereafter the techniques of source coding differ substantially i.e. one technique involves zonal coding, the …
Page 1 of 3