![]() |
![]() |
|
|
||
PNG - Export | ||
Portable Network Graphic Format (PNG), pronounced "ping" is a bitmap file format. It is specifically designed for network image data transmission and storage. It is capable of loslessly storing bi-level to 48 bit true color image data. PNG is a well-designed and well-developed file format that is intended to replace CompuServe's GIF file format. PNG is a newer format that provides inclusion of transparency with a 16 bit alpha channel. EazyDraw and OS X support color transparency. For this reason you may find PNG to be the preferred interchange format for web, network, and computer display applications. This may become more important as more applications add support for transparency. PNG also provides a faster progressive display interlacing scheme than GIF. PNG does not support multiple images per file that are used for storage of animation sequences. The Dots Per Inch (DPI) parameter is used to define the resolution or quality of the exported representation. Normal display screen viewing requires about 72 DPI for acceptable visual quality. Printed applications usually require 300 DPI for good quality representation. High quality printed results may need 600 DPI or greater.
The TIFF documentation page provides the foundation documentation for exporting bitmap data files. Review that information for further details concerning file size, image quality and choice of Dots Per Inch (DPI). We cannot regenerate an EazyDraw vector representation from a PNG export file. If your final work needs to be PNG (or any other bitmap format) be sure to Save and archive the EazyDraw original in case modifications to the original work are needed in the future. You can always generate a revised PNG export from the original-but the reverse is not possible. Compression is lossless and avoids use of the LZW algorithms. The LZW compression algorithms and the GIF file format have become the target of pay-to-implement issues stemming from Compuserve's ownership of the GIF format and licensing of the LZW algorithms. |