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
druckmuller@fme.vutbr.cz
Page last update: 18.3.2007
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