Joint Photographic Experts Group Images Research Articles

The display of photographic-quality images on the Web: a comparison of two technologies

Downloading medical images on the Web creates certain compromises. The tradeoff is between higher resolution and faster download times. As resolution increases, download times increase. High-resolution (photographic quality) electronic images can potentially play a key role in medical education and patient care. On the Internet, images are typically formatted as Graphics Interchange Format (GIF) or the Joint Photographic Experts Group (JPEG) files. However, these formats are associated with considerable data loss in both color depth and image resolution. Furthermore, these images are available in a single resolution and have no capability of allowing the user to adjust resolution as needed. Images in the photo compact disc (PCD) format have higher resolutions than GIF or JPEG, but suffer the disadvantage of large file sizes leading to long download times on the Web. Furthermore, native web browsers are not currently able to read PCD files. The FlashPix format (FPX) offers distinct advantages over the PCD, GIF, and JPEG formats for display of high-resolution images on the Web. A Java applet can be easily downloaded for viewing FPX images. FPX images are higher resolution than JPEG and GIF images. FPX images offer rich resolutions comparable to PCD images with shorter download times.

Blocking effect reduction of JPEG images by signal adaptive filtering

A postprocessing algorithm is proposed to reduce the blocking artifacts of Joint Photographic Experts Group (JPEG) decompressed images. The reconstructed images from JPEG compression produce noticeable image degradation near the block boundaries, in particular for highly compressed images, because each block is transformed and quantized independently. The blocking effects are classified into three types of noises in this paper: grid noise, staircase noise, and corner outlier. The proposed postprocessing algorithm, which consists of three stages, reduces these blocking artifacts efficiently. A comparison study between the proposed algorithm and other postprocessing algorithms is made by computer simulation with several JPEG images.

Using JPEG image compression to facilitate telemedicine

Economical applications of teleradiology and telemedicine are limited to the existing telephone network infrastructure, which greatly limits the speed of digital information transfer. Telephone lines are inherently slow, requiring image transmission times to be unacceptably long for large, complex, or numerous images. JPEG (Joint Photographic Experts Group) image transmission has been shown to compress images to 10% of the original file size without a noticeable change in the quality of the image. This study was carried out to assess the quality of medical diagnostic images after JPEG compression and decompression. X-rays, computed tomography scans, and ultrasound samples were compressed and decompressed using JPEG. The compressed JPEG images were indistinguishable from the original images. The JPEG images were approximately 10% of the original file size. This would reduce image transmission times by 90% (eg, an unacceptable time of 50 minutes would be reduced to an acceptable time of 5 minutes). JPEG can be used to optimize teleradiology and telemedicine.

High resolution still picture transmission system

A 64 kb/s high-resolution still picture ISDN (integrated services digital network) communication system capable of receiving and transmitting a 1024*1024 pixel still picture in approximately 13 s has been developed. An IBM PC-AT and AX-PC compatible picture codec board and an ISDN communication interface board have been designed for use with this system. The JPEG (Joint Photographic Experts Group) image coding algorithm is implemented for image compression to assure ISDN connectivity. In addition to high-resolution still pictures, the system transmits portrait images of the user. This system can be used for a wide range of applications, including simple video conference systems.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>