Picsel ePAGE Bitmap Image file format support
Picsel Image File Format Support Page 2 Copyright Copyright © Picsel 2002 Neither the whole nor any part of the information contained in, or the product described in, this document may be used, sold, transferred, adapted or reproduced in whole or in part in any manner or form or in any media except with the prior written permission of the copyright holder. The product described in this document is subject to continuous development and improvement.
Picsel Image File Format Support Page 3 Introduction On handheld computers, traditional applications typically rely on synchronization with a PC to convert content from the original document format into a simpler format used by the device. This creates at least three problems. Firstly, some visual integrity is inevitably lost in the conversion process from a rich format to a simpler one, resulting in documents that do not look exactly like the original.
Picsel Image File Format Support Page 4 ePAGE supports the most popular global file formats. The formats interpreted by ePAGE are richly expressive, containing not just text but sophisticated layout and rendering features, rich fonts, colour, images, tables, graphics and many other document features. Picsel is continuously developing its file format support to eventually cover every feature of the native file.
Page 5 Picsel Image File Format Support JPEG JPEG is a format defined by the ISO Joint Photographic Experts Group. It is well suited to efficient compression of photographs, which it does by deleting unimportant content according to the kind of detail that people notice; in particular, it removes more chrominance (colour) information than luminance (brightness), since the human eye is more sensitive to luminance.
Page 6 Picsel Image File Format Support GIF GIF, the CompuServe Graphics Interchange Format, is widely used on web pages. It can store interlaced rows of pixels, appearing as progressive rendering, as well as binary transparency and animation. It supports a maximum of 256 indexed colours, but no full-colour images. GIF uses LZW compression to encode repeating patterns of pixels of certain colours and save file sizes, but the animation requires reencoding of the image, which wastes space.
Page 7 Picsel Image File Format Support PNG The Portable Network Graphic (PNG) format, does not use any patented or proprietary methods, and is intended as a replacement for GIF. Its compression is good for cartoons and diagrams; less so for photographs. PNG supports progressive rendering using two dimensional interlacing, alpha-channel transparency, as well as gamma correction and indexed colour. It supports up to 48 bits of full colour or 16 bits of grey-scale, per pixel.
Page 8 Picsel Image File Format Support BMP Windows Bitmap (BMP) is a format used by MS Windows and other programs which value simplicity over economy. BMP files are almost always uncompressed and so very large. BMP can include 1, 4, 8 or 24 bits per pixel, allowing both indexed and full colour. Neither transparency nor animation are supported.
