Always download the last full version from Aminet before you update:
Aminet - util/libs/IconLib_46.4.lha
Added a new 46.4.507_LD020:
This is mixture of the old LD020 using the line by line drawing mode for ColorIcons and TC020 for the OS4 and PNG icons. It depends on the hardware whether this new LD020 or the original TC020 is faster for displaying ColorIcons on Hi/TrueColor screens.
Update to icon.libary 46.4.508:
This update supports the PNG icon "Frameless" flag now and the TrueColor mode can be disabled with the command "ConvertTrueColor" to create icons in the OS 3.5 format or "RestoreTrueColor" to switch back to TC mode again. You'll need to update the windows after changing the mode. The "Frameless" flag can be set with RAWBInfo or Report+ for example.
Update to icon.libary 46.4.509:
Cleaned up and streamlined the gfx-patch a bit. Renamed "RestoreTrueColor" into "PreserveTrueColor".
A dirty and risky experiment in Area 51: 
Since it's not allowed to enter this forbidden zone icon.library now pretends to be V51 to get into it without accepting the rules which could be dangerous.
Icon.library 51.4.510 TC020 only supports one of the new V51 features to let the tool Eastern render its thumbnail preview icons for your pictures as ARGB TrueColor images by using IconControlA() and SetImageDataFormat even under OS 3.x. This gives much better quality than the poor dithering of Eastern that it uses for V44 libraries. This version is not made for OS4, of course. The preview icons can not be saved in TrueColor like they are displayed, they are converted into the OS 3.5 format with 255 colors then, but that's still looking better than the dithered icons created by Eastern. Please report any conflicts from Area 51.
http://aminet.net/package/util/wb/eastern
If you want to create icons for your pictures permanently then better use Image2Icon and i2iGUI and select the OS4 TrueColor format for the images. This also works with icon.library v46.
http://aminet.net/package/util/wb/image2icon
http://aminet.net/package/util/wb/i2iGUI-V2
Btw, AfA_OS has a patch for DOpus 5.82 to support DefIcons and Eastern instead of the FileType definitions. This also works in Area 51.
Update to icon.libary 46.4.511:
This is a small bugfix for the color reduction. This bug was probably never visible yet for icons with transparency until I made my experiment in Area 51 with Eastern and its opaque preview images, where very rarely some black pixels appeared at the top of some color mapped icons. Sometimes my test for color repetitions has compared the first pixels with a value outside of the images and for the rare case of matching values this bug got visible.
Added IconDemoHAM6 and IconDemoHAM8 ADF images.
All IconDemos need Kickstart 3.0 or better 3.1, but are not made for 3.1.4, because the workbench.library is missing and the WB 3.1.4+ also requires a different FBlit.cfg and DefIcons.
Updated IconDemo ADF files (486):
To make it easier to use my icon.library under OS 3.0/3.1, I've built two demo floppy images that should show you how to get things to work. Just copy one of these ADF files onto a floppy disk and then boot from it. These images are NO speed demos! If you have enough RAM you could also use the much faster RAD: disk. (Please, always install the latest icon.library on your harddisk)
These demos can display all types of icons: old icons, MWB-icons, NewIcons, GlowIcons, OS4-icons and PNG-icons. This does not need a workbench.library v44+. Only the old icon.library is removed from the resident list with Thomas Rapp's very nice RemLib tool and then the new icon.library is loaded from Libs: into the memory instead, without a reboot.
IconDemoA500.ADF is for low end systems
with 68000+ CPUs, OCS/ECS with a fixed 16 color palette, minimal 512 kB ChipMem and 1 MB FastMem. I would recommend at least 40 MHz and more memory to enjoy it (e.g. a MiniMig). 68020+ systems are detected and supported by loading the 68020 version automatically.
IconDemoA1200.ADF is for better systems
with 68020+ CPUs, AGA, minimal 1 MB ChipMem and 2 MB FastMem and uses FBlit. It needs no ChipMem for the icons and the NewIcons patch makes even transparent backgrounds possible.
In both configurations DefIcons, AutoUpdateWB and SwazInfo are also installed. These ADFs are working with Kick 3.0 already and are supporting PAL and
now also NTSC screenmodes.
The excellent CopyIcon tool from Stephan Rupprecht makes it possible to replace the images on your existing icons with a simple drag&drop from all available icon sets, no matter which format the source icons have.
Of course, the icon loading from a floppy disk will always be very slow. Furthermore, OS4 and PNG icons can also be rendered much faster after converting them once into the OS 3.5 format, but on these ADFs they are still in their original file format in order to demonstrate the ability to decode them on any Amiga.