Adaptive postfiltering of 16 kb/s-ADPCM speech

Jayant, N.; Ramamoorthy, V.

doi:10.1109/icassp.1986.1168985

Cited by 18 publications

(5 citation statements)

References 4 publications

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“…Spatial redundancy: Spatial decorrelation methods, like prediction or transformation [11], are usually employed to remove spatial redundancy. Prediction-based techniques: are used to predict the current pixel value from neighboring pixels, such as the Differential Pulse Code Modulation (DPCM) [12]. Transformation-based techniques: are used to transform an image from the spatial domain to either frequency or wavelet domains, mainly such as the Discrete Cosine Transform (DCT) [13] or the Discrete Wavelet Transform (DWT) [14].…”

Section: Types Of Redundancymentioning

confidence: 99%

Image Compression Techniques on-Board Small Satellites

Shihab

2023

Iraqi Journal of Science

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Raw satellite images are considered high in resolution, especially multispectral images captured by remote sensing satellites. Hence, choosing the suitable compression technique for such images should be carefully considered, especially on-board small satellites, due to the limited resources. This paper presents an overview and classification of the major and state-of-the-art compression techniques utilized in most space missions launched during the last few decades, such as the Discrete Cosine Transform (DCT) and the Discrete Wavelet Transform (DWT)-based compression techniques. The pros and cons of the onboard compression methods are presented, giving their specifications and showing the differences among them to provide unified information about these methods for researchers and satellite imaging payload designers. Hence, some of these techniques are implemented, and comparisons are presented in the current work as examples to simulate an image compression system on board a small satellite using the MATLAB software package. This was achieved by employing three LANDSAT8, band6 satellite images. A wavelet selection was also considered for the DWT-based compression method, which gave the best results among the other methods through acquiring high values of compression ratio (CR) while maintaining the important scientific information of the image when reconstructed at the ground station.

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Section: Types Of Redundancymentioning

confidence: 99%

Image Compression Techniques on-Board Small Satellites

Shihab

2023

Iraqi Journal of Science

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“…The idea of the adaptive postfilter based on the LP synthesis filter and used to reduce the perceptible noise was first introduced in Ref. 25. The adaptive postfilter is an additional linear filter that is combined with the synthesis filter to accomplish this.…”

Section: More Uses For Perceptual Maskingmentioning

confidence: 99%

Current Methods of Speech Coding

Cox

1997

Selected Topics in Electronics and Systems

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Digital speech coding is used in a wide variety of every day applications that the ordinary person takes for granted, such as network wireline and cellular telephony and telephone answering machines. This article reviews some of the most currently used methods of speech coding. This includes reviewing the basic attributes of these coders, the methods used for coding and some of the most important speech coding standards. It also reviews the methods used to realize digital speech coders, especially those for implementing these coders in a cost effective manner.

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“…On the other hand, the postfiltering operation introduces distortion in the speech signal to sorne degree [113]. In this coder, the filter paramcters and the codebook entries are selected by minimizing a noise-weighted mean square error and/or using noise shaping filters.…”

Section: Perceptual Noise Weightingmentioning

confidence: 99%