Image quality of the compressed pictures can be evaluated by objective testing method based on the lower level human visual system model. The simulation of the HVS model presented here is used either to show the region in a compressed picture where the distortion is visible or can produce a single image quality number which correlates well with subjective image quality evaluation. Sets of the p...

It is important to transmit pictures efficiently in most Web sites, especially for those users with low bandwidth connections. In this demonstration, we propose a system which progressively transmits images using a very low transmission rate (as low as 15% in some cases). The transmitted images maintain a reasonable picture quality for the users to browse images quickly. Interested readers can ...

The ITU Radiocommunication Assembly, considering a) that with the increasing application of digital coding and bit-rate reduced transmission, the assessment of coding impairments is of critical importance; b) that objective measurements are necessary for specific evaluations as routine supervisions or system optimizations; c) that several types of objective measurements may be defined for diffe...

An imposing number of lossy compression techniques used in medicine, represents a challenge for the developers of a Picture Archiving and Communication System (PACS). How to choose an appropriate lossy medical image compression technique for PACS? The question is not anymore whether to compress medical images in lossless or lossy way, but rather which type of lossy compression to use. The numbe...

Several recent studies have shown that while iris images captured at near infrared are viable biometrics for verification and identification, similar to other biometrics, its performance drops when comparing images from imperfect sources (e.g. subject blinking), under imperfect conditions (e.g. out of focus) or non-ideal capture device. The immediate question to ask is what factors and to what ...

Several problems arise among the existing LSB-based image steganographic schemes due to distortion in a stegoimage and limited payload capacity. Thus, a proposed scheme has been developed with the aims to help in improving the payload of the secret data at the same time retaining the quality of the stego-image produced within an acceptance threshold. This study has led to the modification of th...

Image quality assessment (IQA) is a crucial technique in perceptual image/video coding, because it is not only a ruler for performance evaluation of coding algorithms but also a metric for ratio-distortion optimization in coding. In this paper, inspired by the fact that distortions of both global and local information influence the perceptual image quality, we propose a novel IQA method that in...

In this paper, a tolerance of distortion in picture quality was investigated quantitatively for a distance learning using a DV(Digital Video) movie. The subjective evaluations were made for a face-to-face type and a presentation type of lectures. By factor analysis, the five factors were obtained: "the picture quality", "the sensation of presence", "the comprehensibility", "the advantage of a d...

Segmentation is often a procedure to group spatially adjacent image pixels into segments. Spatially adjacent pixels form one image segment if they meet some criteria, such as spectral similarity. A segmentation result may vary, depending on a given generalization level and other constraints such as compactness. In practice, the quality of a segmentation result is often assessed visually by the ...

A simulation based on Gilbert-Elliot packet loss model is developed to simulate an image transmitting system in underwater acoustic channel. This developed system is applied as a platform to study the relation between image quality assessment parameter PSNR, image activity measure (IAM) and channel’s packet loss rate. A group of sample images were transmitted in this communication system and a ...