Nanna Suryana

A generic psychovisual error threshold for the quantization table generation on JPEG image compression

The quantization process is a main part of image compression to control visual quality and the bit rate of the image output. The JPEG quantization tables are obtained from a series of psychovisual experiments to determine a visual threshold. The visual threshold is useful in handling the intensity level of the colour image that can be perceived visually by the human visual system. This paper will investigate a psychovisual error threshold at DCT frequency on the grayscale image. The DCT coefficients are incremented one by one for each frequency order. Whereby, the contribution of DCT coefficients to the error reconstruction will be a primitive pyschovisual error. At certain threshold being set on this psychovisual error, the new quantization table can be generated. The experimental results show that the new quantization table from psychovisual error threshold for DCT basis functions gives better quality image at lower average bit length of Huffman code than standard JPEG image compression.

ADAPTIVE TCHEBICHEF MOMENT TRANSFORM IMAGE COMPRESSION USING PSYCHOVISUAL MODEL

An extension of the standard JPEG image compression known as JPEG-3 allows rescaling of the quantization matrix to achieve a certain image outp ut quality. Recently, Tchebichef Moment Transform (TMT) has been introduced in the field of image compression. TMT has been shown to perform better than the standard JPEG image compression. This study presents an adaptive TMT image compression. This task is obtained by generating custom quantization tables f or low, medium and high image output quality levels based on a psychovisual model. A psychovisual model is developed to approximate visual threshold on Tchebichef moment from image reconstruction error. The contribution of each moment will be investigated and analy zed in a quantitative experiment. The sensitivity of TM T basis functions can be measured by evaluating the ir contributions to image reconstruction for each mome nt order. The psychovisual threshold model allows a developer to design several custom TMT quantization tables for a user to choose from according to his or her target output preference. Consequently, these quant ization tables produce lower average bit length of Huffman code while still retaining higher image quality tha n the extended JPEG scaling scheme.

Image watermarking using psychovisual threshold over the edge

Currently the digital multimedia data can easily be copied. Digital image watermarking is an alternative approach to authentication and copyright protection of digital image content. An alternative embedding watermark based on human eye properties can be used to effectively hide the watermark image. This paper introduces the embedding watermark scheme along the edge based on the concept of psychovisual threshold. This paper will investigate the sensitivity of minor changes in DCT coefficients against JPEG quantization tables. Based on the concept of psychovisual threshold, there are still deep holes in JPEG quantization values to embed a watermark. This paper locates and utilizes them to embed a watermark. The proposed scheme has been tested against various non-malicious attacks. The experiment results show the watermark is robust against JPEG image compression, noise attacks and low pass filtering.

Spectrum Analysis of Speech Recognition via Discrete Tchebichef Transform

Speech recognition is still a growing field. It carries strong potential in the near future as computing power grows. Spectrum analysis is an elementary operation in speech recognition. Fast Fourier Transform (FFT) is the traditional technique to analyze frequency spectrum of the signal in speech recognition. Speech recognition operation requires heavy computation due to large samples per window. In addition, FFT consists of complex field computing. This paper proposes an approach based on discrete orthonormal Tchebichef polynomials to analyze a vowel and a consonant in spectral frequency for speech recognition. The Discrete Tchebichef Transform (DTT) is used instead of popular FFT. The preliminary experimental results show that DTT has the potential to be a simpler and faster transformation for speech recognition.

Crowd event detection in computer vision

One of video surveillance applications is crowd analysis. Video surveillance application uses crowd analysis for automatic detection of anomalies and alarms. Behavior of the crowd attracts many researchers interest because of its complexity and abstract. Several obstacles, such as, occlusion, illumination changes, and any other obstacles that could influence detecting process, also there are some difficulties in analyzing crowd event. This paper is intended to analyze crowd behavior through video surveillance for detecting normal and abnormal pattern. In addition, two basic methods in segmentation from sequence images are compared.

A Psychovisual Threshold for Generating Quantization Process in Tchebichef Moment Image Compression

A human visual system can hardly respond to small differences in image signals. A full colour image carries a certain amount of perceptual redundancy for the human eyes. The sensitivity human eye of the color image can be measured by a psychovisual threshold. The sensitivity of the human eye is useful for perceptual visual image in image compression. The quantization tables are obtained to determine psychovisual threshold that can be perceived visually significant by the human eye. This paper introduces the concept of psychovisual threshold into Tchebichef moment image compression. This paper will investigate the contribution of each moment coefficient to the image reconstruction. The error threshold from the contribution of its moments in image reconstruction will be the primitive of psychovisual threshold to an image. This paper presents a new technique to generate quantization table for an optimal TMT image compression based on psychovisual error threshold. The experimental results show that these new finer quantization tables provide a statistically better image quality output at lower average bit length of Huffmans code than previously proposed TMT quantization.

A Data Mining Approach for Developing Quality Prediction Model in Multi-Stage Manufacturing

prediction model has been developed in various industries to realize the faultless manufacturing. However, most of quality prediction model is developed in single-stage manufacturing. Previous studies show that single-stage quality system cannot solve quality problem in multi-stage manufacturing effectively. This study is intended to propose combination of multiple PCA+ID3 algorithm to develop quality prediction model in MMS. This technique is applied to a semiconductor manufacturing dataset using the cascade prediction approach. The result shows that the combination of multiple PCA+ID3 is manage to produce the more accurate prediction model in term of classifying both positive and negative classes.

Flexible Data Warehouse Parameters: Toward Building an Integrated Architecture

Clinical databases have gathered a huge amount of information about patients and their medical conditions. Relationships and patterns within this data could provide new medical knowledge. Thus it is a difficult task focusing to model a data warehouse, very often, into internal structures and implementation applications. The aim of is project is to find the parameters of medical data warehouse which will be able to construct a flexible framework by analyze the approaches of data warehouse architectures and compare them regarding the cost and integrity. The proposed parameters may assist in achieving continual access to the common data warehouse. The important consideration, however, is that the clinical data record should contain not only longitudinal health summary information but also be used for business intelligence tool such as data mining and OLAP

Integrating a Smooth Psychovisual Threshold into an Adaptive JPEG Image Compression

The visual quality image output of JPEG compression is determined by quantization process. The popular quality factor in the extended JPEG image compression has been widely used to scale up the quantization tables. The scaling quantization table using quality factor is used to determine the quality image output. The scaling up on the quantization tables increases their values uniformly thus produces higher compression performance. However, the effects of the scaling up on the human visual system have not been taken into consideration. This paper examines the quantization table design based on adaptive psychovisual threshold and numerical analysis of the compression performance in terms of quality image reconstruction and average bit length of Huffman code. The comparison between extended JPEG image compression using the typical quality factor and quality scale of psychovisual threshold has been done. The experimental results of adaptive quantization tables based on psychovisual threshold show an improvement on the quality of image reconstruction at the lower average bit length of Huffmans code.

AN IMAGE DITHERING VIA TCHEBICHEF MOMENT TRANSFORM

Many image display applications and printing device s allow only limited number of colours. They have limited computational power and storage to produce high quality outputs on high bit-depth colour image . A dithering technique is called for here in order to improve the perceptual visual quality of the limite d bitdepth images. A dithered image is represented by a natural colour in the low bit depth image colour fo r displaying and printing. This technique obtains low cost colour image in displaying the colour and pri nting image pixels. This study proposes the dithering tec hnique based on Tchebichef Moment Transform (TMT) to produce high quality image at low-bit colour. Ea rlier, a 2 ×2 Discrete Wavelet Transform (DWT) has been proposed for better image quality on dithering . The 2 ×2 TMT has been chosen here since it performs better than the 2 ×2 DWT. TMT provides a compact support on 2 ×2 blocks. The result shows that 2 ×2 TMT gives perceptually better quality on colour image d ithering in significantly efficient fashion.