In this paper, we propose a novel compression scheme for medical images with extended bit depth. Our scheme efficiently utilizes the VOI (value of interest) settings of the medical images, so that only a small part of...
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ISBN:
(纸本)9781424456536
In this paper, we propose a novel compression scheme for medical images with extended bit depth. Our scheme efficiently utilizes the VOI (value of interest) settings of the medical images, so that only a small part of the coded bit-stream is needed at the decoder to lossless display the original image with recommended VOI parameters. Gray-Golomb coding is used to support VOI progressive transmission. In addition, the pixel domain bit-plane coding enables accurate distortion estimation at pixel level for any truncated bit-stream. Compared to JPEG2000, our scheme achieves much higher VOI performance with very slight overall bit-rate increase.
Denoising of medical images in wavelet domain has potential application in transmission technologies such as teleradiology. This technique becomes all the more attractive when we consider the progressive transmission ...
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ISBN:
(纸本)0819461032
Denoising of medical images in wavelet domain has potential application in transmission technologies such as teleradiology. This technique becomes all the more attractive when we consider the progressive transmission in a teleradiology system. The transmitted images are corrupted mainly due to noisy channels. In this paper, we present a new real time image denoising scheme based on limited restoration of bit-planes of wavelet coefficients. The proposed scheme exploits the fundamental property of wavelet transform - its ability to analyze the image at different resolution levels and the edge information associated with each sub-band. The desired bit-rate control is achieved by applying the restoration on a limited number of bit-planes subject to the optimal smoothing. The proposed method adapts itself to the preference of the medical expert;a single parameter can be used to balance the preservation of (expert-dependent) relevant details against the degree of noise reduction. The proposed scheme relies on the fact that noise commonly manifests itself as a fine-grained structure in image and wavelet transform allows the restoration strategy to adapt itself according to directional features of edges. The proposed approach shows promising results when compared with unrestored case, in context of error reduction. It also has capability to adapt to situations where noise level in the image varies and with the changing requirements of medical-experts. The applicability of the proposed approach has implications in restoration of medical images in teleradiology systems. The proposed scheme is computationally efficient.
The statistical model of the bits to be encoded is crucial for the coding performance of distributed video coding (DVC). In this paper, a bit-level context-adaptive correlation model is proposed to exploit high-order ...
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ISBN:
(纸本)9781479947614
The statistical model of the bits to be encoded is crucial for the coding performance of distributed video coding (DVC). In this paper, a bit-level context-adaptive correlation model is proposed to exploit high-order statistical correlation for better channel coding performance, which consequently improves the video coding efficiency. In the proposed scheme, the wavelet domain DVC is considered and the coefficients are coded in a bit-plane fashion. The context for each bit to be coded is first formed. Then the probability distribution of each bit is estimated by using previously available data with the same context. For magnitude coding, the significant state of the following elements are included in the context, (1) the side information, (2) the local neighborhood, (3) the parent coefficients (if applicable). The condition of side information is considered as well. For sign coding, the context consists of the sign and the quality of the side information. The proposed model is implemented within a recently proposed DVC framework with decoder-side multi-resolution motion refinement (MRMR). Experimental results show the effectiveness of the proposed scheme with significant coding gain over the original MRMR based DVC system, especially for videos with high motion intensity and for lower bit rates.
In this paper, we propose a joint source-channel coding (JSCC) scheme for image transmission over wireless channel. In the scheme, fountain codes are integrated into bit-plane coding for channel coding. Compared to tr...
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ISBN:
(纸本)9780819485762
In this paper, we propose a joint source-channel coding (JSCC) scheme for image transmission over wireless channel. In the scheme, fountain codes are integrated into bit-plane coding for channel coding. Compared to traditional erasure codes for error correcting, such as Reed-Solomon codes, fountain codes are rateless and can generate sufficient symbols on the fly. Two schemes, the EEP (Equal Error Protection) scheme and the UEP (Unequal Error Protection) scheme are described in the paper. Furthermore, the UEP scheme performs better than the EEP scheme. The proposed scheme not only can adaptively adjust the length of fountain codes according to channel loss rate but also reconstruct image even on bad channel.
In this paper, we propose two enhanced elements on the wavelet-based contourlet transform (WBCT) image coding scheme. A short-length 2-D non-separable directional filter bank is designed for significantly reducing the...
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ISBN:
(纸本)9781424417650
In this paper, we propose two enhanced elements on the wavelet-based contourlet transform (WBCT) image coding scheme. A short-length 2-D non-separable directional filter bank is designed for significantly reducing the calculation. New zero coding context models are designed to improve coding efficiency. Experiments show that the proposed compression scheme produces better visual quality images, particularly, with fine and regular texture at low rates. The short-length directional filter bank performs nearly as well as their long-length counterpart.*
Watermarking, traditionally used for copyright protection, is used in a new and exciting way. An efficient wavelet-based watermarking technique embeds audio information into a video signal. Several effective compressi...
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ISBN:
(纸本)0819441864
Watermarking, traditionally used for copyright protection, is used in a new and exciting way. An efficient wavelet-based watermarking technique embeds audio information into a video signal. Several effective compression techniques are applied to compress the resulting audio/video signal in an embedded fashion. This wavelet-based compression algorithm incorporates bit-plane coding, index coding, and Huffman coding. To demonstrate the potential of this audio embedding and audio/video compression algorithm, we embed an audio signal into a video signal and then compress. Results show that overall compression rates of 15:1 can be achieved. The video signal is reconstructed with a median PSNR of nearly 33 dB. Finally, the audio signal is extracted from the compressed audio/video signal without error. The views expressed in this article are those of the authors and do not reflect the official policy or position of the United States Air Force, Department of Defense, or the U. S. Government.
The JPEG2000 coding scheme is slowly getting into use in imaging applications. The standard offers a set of new features and a better compression efficiency compared to the baseline JPEG. It requires, however, a high ...
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ISBN:
(纸本)0819461172
The JPEG2000 coding scheme is slowly getting into use in imaging applications. The standard offers a set of new features and a better compression efficiency compared to the baseline JPEG. It requires, however, a high computational cost, making its usage in constrained devices, such as mobile phones or PDAs, challenging. We present a pre-compression rate allocation technique to reduce the encoding complexity and help adoption of JPEG2000 in such contexts.
In scalable audio coders, such as the MPEG-4 SLS, error-mapping is used to map quantization errors in the core coder to an error signal before passing through bit-plane coding. In this paper, we propose a new error-ma...
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ISBN:
(纸本)9781479958962
In scalable audio coders, such as the MPEG-4 SLS, error-mapping is used to map quantization errors in the core coder to an error signal before passing through bit-plane coding. In this paper, we propose a new error-mapping scheme that is derived by observing statistical properties of the error signal. Compared with the error-mapping in SLS, the proposed scheme improves coding efficiency as well as computational complexity of the coder. An average improvement of 9 points in MUSHRA score has been achieved by the proposed scheme in subjective listening tests. The proposed error-mapping adds a useful new tool to the existing toolset for constructing next-generation scalable audio coders.
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