## There is now a script utils/mk_jalview_icons.sh that creates the .icns and .ico icon files, and also the rotatable icon.
Run it as
```
mk_jalview_icons.sh <BASENAME>-512.png
```
Having an existing 512x512 PNG image with the above filename format is important.
It will then create multiple files
`<BASENAME>-<N>.png`
for N being 16, 32, 38, 48, 64, 128, 256.
**NB** You might want to edit these as described below.  The `mk_jalview_icons.sh` will not overwrite these files, but it
will overwrite the `.ico` and `.icns` files, so after editing the `<BASENAME>-<N>.png` files, just run the script again.

As below, the script relies on ImageMagick and icnsutils being installed with `convert` and `png2icns` in the PATH.

The rotatable logo will also be created (and overwritten) as
`rotatable_<BASENAME>-38.png`


## Old text
### Creating the .ico (Windows) and .icns (macOS) files from PNG images in linux

Create multiple square versions of your icon at the following resolutions:
16x16, 32x32, 48x48, 64x64, 128x128, 256x256, 512x512

> A quick way to do this with ImageMagick is create the 512x512 logo first, saved as logo-512.png, and run
> `for n in 16 32 48 64 128 256; do convert -geometry ${n}x${n} logo-512.png logo-${n}.png; done`
> but note that anitaliasing can make a logo look quite blurry, especially for small resolutions.  These should
> then be hand edited (with e.g. gimp) to neaten the edges.  A nice trick in gimp is to use the Colours->Curves->Alpha
> and create a curve that makes mostly transparent pixels completely transparent, and slightly transparent pixels
> completely opaque.

Then use the script `jalview/utils/create_iconfiles.sh` like this:
```
create_iconfiles.sh logo-*.png
```
and it will create both `logo.ico` and `logo.icns` containing the appropriate different resolution logos.
It is then up to the OS to display the correct one in different circumstances.

This script uses the utilities convert (ImageMagick) and png2icns (icnsutils) which should be installed and in the path.
Note that for some reason ICNS files should not contain a 64x64 pixel version of a logo, so the script removes this
as png2icns complains if it finds one!

### Rotatable icon with white background

This icon is used by the web services progress window, with the rotating Jalview logo.
It requires some small margin of white pixels around the logo to enable antialiasing around the edge of the logo.
You can make one form a 38x38 transparent logo with
```
convert jalview_logo-38.png -gravity center -background white -extent 60x60 rotatable_jalview_logo-38.png
```