Re: 256x256 px icons

[Charles Wilson <cygwin@cwilson.fastmail.fm>]

On 7/27/2011 1:30 PM, Warren Young wrote:
> - Do we need more sizes?  I've seen reference to odd sizes like 64x64
> and 96x96, but surely we can trust Vista+ to scale the 256x256 to these
> sizes without needing hand-tweaked versions?
> 
> - Something I read talked about the 16x16 being 4bpp, but I can't see a
> need for that since the the old Windows 95 Plus Pack days.  Everything
> from Win98 up should actually be fine with 16bpp and up.  The only
> reason I used 8bpp for the smallest ones is that's a big enough box of
> crayons.

Read this:
/usr/share/doc/cygutils/cygicons/README
==============================================================
First, 4bpp is not just ANY 16 colors. Its required to be exactly the
old EGA colors.

8bpp can use any 256 colors, but many use the web-safe 216, plus 40
others. These don't support alpha, but just a single 'transparent'
color. Windows XP style guidelines say that magenta (#ff00ff) should be
used for this purpose.

24bpp has no alpha, instead uses a single color (out of your 16M) for
transparency.

32bpp is the only one with alpha.

Main icon sizes:
----------------
   16x16    : used on the TaskBar
   24x24    : uncommon. used on the left half of
              the Start Menu in Windows XP.
   32x32    : default icon size for desktop icons
   48x48    : DisplayProperties->Appearance->Advanced,
              Item=Icon, set size.  Not often used.
   64x64    : New icon size for Vista.
   256x256  : New icon size for Vista. Stored in compressed
              PNG format within the .ico file; completely
              violates all the rules described above.
==============================================================
plus:
http://msdn.microsoft.com/en-us/library/ms997636.aspx (WinXP icon style
guide)

Icon Sizes
There are four sizes of Windows icons—48 × 48, 32 × 32, 24 × 24, and 16
× 16 pixels.

We recommend that your icon contains these three sizes:
    48 × 48 pixels
    32 × 32 pixels
    16 × 16 pixels

Each Windows XP icon should contain these three color depths to support
different monitor display settings:

    24-bit with 8-bit alpha (32-bit)
    8-bit (256 colors) with 1-bit transparency
    4-bit (16 colors) with 1-bit transparency
==============================================================
and
http://msdn.microsoft.com/en-us/library/aa511280.aspx (Vista style guide)

Icon files require 8-bit and 4-bit palette versions as well, to support
the default setting in a remote desktop. These files can be created
through a batch process, but they should be reviewed, as some will
require retouching for better readability.

Bit levels: ICO design for 32-bit (alpha included) + 8-bit + 4-bit
(dithered down automatically—pixel poke only most critical). Only a
32-bit copy of the 256x256 pixel image should be included, and only the
256x256 pixel image should be compressed to keep the file size down.
Several icon tools offer compression for Windows Vista.

Bit levels: Toolbars 24-bit + alpha (1 bit mask), 8-bit and 4-bit.
Toolbars or AVI files: Use magenta (R255 G0 B255) as the background
transparency color.

Application icons and Control Panel items: The full set includes 16x16,
32x32, 48x48, and 256x256 (code scales between 32 and 256). The .ico
file format is required. For Classic Mode, the full set is 16x16, 24x24,
32x32, 48x48 and 64x64.

Additional sizes: These are useful to have on hand as resources to make
other files (for example, annotations, toolbar strips, overlays, high
dpi, and special cases): 128x128, 96x96, 64x64, 40x40, 24x24, 22x22,
14x14, 10x10, and 8x8. You can use .ico, .png, .bmp, or other file
formats, depending on code in that area.

[ed: uhm, NO. NO NO NO to 128, 96, 40, 22, 14, 10, and 8.]

==============================================================

>> The only problem to look out for is licensing.  If you use foreign
>> art, you have to make sure that the icon is published under a free
>> license.
> 
> There are two source pieces, the fattbuttlary Cygwin icon and the KDE
> Konsole icon.  I assembled and massaged them on work time.  Red Hat has
> a copyright assignment on file for me, from way back.

the fatbuttlarry icon is GPL.
not sure about the KDE Konsole icon.

--
Chuck