Graphical Formats Information

PNG format - images

All important images on my Web pages are in PNG (Portable Network Graphics) format. This format uses lossless compression and preserves the original quality of images. Nowadays, as far as I know, PNG format is supported by all Web browsers. If your Web browser is not able to display images in this format, you have probably a very old version and you should update it. Lossless compression is not so effective as lossy compression of JPEG format and therefore the downloading of images may by slower than you are used to. That is why I made a lower quality version (JPEG format) for each page which needs more than 100 KB to download. If you have a slow Internet connection, you should better view these pages. The images degradation by lossy compression is often visible by careful comparing with the image original only, regardless it may cause changes, for example in coronal structures, which may be misinterpreted. For that reason, if you want to use any image for scientific purposes, download it in PNG format.

Using of PNG format may solve the problem that images made on PC look badly on Mac and vice versa. It is because of different display gamma setting. PNG format may contain gamma information, which is necessary for correct image display. I haven't used this solution yet. My computer is PC and nowadays all images are saved in PNG format without gamma information. It means that these images have correct outlook on PC, but different one on Mac. Simple but uncomfortable solution is to set display gamma to 2.2 value (PC standard). In the near future there will be all high resolution images available in PNG format with gamma information too. I am working on the problem now.

MNG format - animations

All animation used directly in may Web pages are in the MNG (Multiple-image Network Graphics) format. This format gives better quality (16 M colors instead of 256) and better compression ratio than the animated GIF format. Nowadays, this format is supported natively by some Web browsers, for the others there are easy to install freeware plug-ins. Solutions for various Web browsers follow.

Mozilla, Netscape for Windows
Several versions of Mozilla and Netscape have the native support of this format. If you use a version without the MNG format support, you can solve the problem very easily in the same way as it is recommended for Opera.

Opera, Firebird, Firefox for Windows
These browsers do not support this format natively but the solution is very simple. You may download the freeware plug-in (created by Jason Summers). To install it, unpack the ZIP file and simply copy the included "npmngplg.dll" file to your browser's "Plugins" folder, then restart your browser. To uninstall, delete the "npmngplg.dll" file. It does not create any other files and it does not write anything to the Windows registry. For more information and copyright notice read in ZIP file included text file.

MS Internet Explorer for Windows
MNG format is not supported by MS Internet Explorer natively. For versions 3, 4, 5, the solution explained for Opera can be used too. With newer versions it does not work. Fortunately, there exists freeware ActiveX control for displaying MNG animations in Internet Explorer for Windows which is very easy to install and work with version 4 and any newer. To install it, download the ZIP file and unpack it in some created directory. Then run "reg.but". Uninstallation is done by running "unreg.bat" and if you wish, deleting the directory with files you unzipped. For more information and copyright notice read in ZIP file included text file.

Linux Web browsers
MNG format is well supported by Linux Web browsers. If your browser does not support this format, you find the solution here.

Mac Web browsers
I have no direct experience with Mac computers. According to information found on Internet MNG format is natively supported by Apple Safari, Netscape and Camino. If your browser does not support this format, I find the solution here.

Display of downloaded MNG animations on PC with Windows
If your computer is PC with MS Windows and you have no program which is able to work with MNG animations and PNG images, I recommend you excellent freeware Irfanview.

The most important link
The most complete information about PNG / MNG format can be found on Portable Network Graphics Home Site.

Miloslav Druckmüller
Institute of Mathematics, Faculty of Mechanical Engineering
Brno University of Technology, Czech Republic
Page last update: 18.3.2007