IconPie
A simple command-line tool to generate application icons from raster graphics or vector graphics images.
Quickly combine multiple images and create professional-looking icons for most versions of Windows, macOS, iOS & Linux.
Features
- Simple interface.
- Sane defaults for the domain of icon composition.
- Supports outputting to
stdout, allowing for piping. - Available as a single executable.
Overview
An icon consists of a set of entries. An entry is simply an image that has a particular size. For example, this is an icon that has a 32x32 entry, a 64x64 entry and a 128x128 entry:

What does it do?
Notice that, in the example above, most entries are basically the same picture re-scaled to multiple sizes. IconPie simply automates the process of re-scaling the picture and combining those re-scaled entries into an icon.
How does it do it?
Re-scaling
When re-scaling pictures, IconPie preserves their original aspect-ratios. It also ensures that the all re-scaled images are square, by adding transparent borders if necessary. If the picture presents a transparent background, the transparency is preserved in the re-scaled images.

Interpolation
For raster graphics (jpeg, png, ...), IconPie
uses nearest-neighbor interpolation
by default, optimizing for small-resolution images.
Furthermore, when using nearest-neighbor interpolation, it only up-scales images on an integer scale, preserving as much detail as possible.

You can choose to opt-out of the default interpolation scheme for raster graphics by specifying a
resampling filter with the -r flag, as described in the Usage section.
For vector graphics (svg),
IconPie always uses linear interpolation
regardless of any specified resampling filter.
Usage
The formal docopt syntax for using IconPie is as follows:
$ icon-pie ((-e <file path> <size>... [-r (nearest | linear | cubic)])... (-ico | -icns | -png) [<output path>]) | -h | --help | -v | --version
-e <options>Specify an entry's source image, target sizes and resampling filter (optional).-r <filter>Specify a resampling filter:nearest,linearorcubic. Defaults tonearest.-ico [<output path>]Outputs to an.icofile. If no output path is specified the app outputs tostdout.-icns [<output path>]Outputs to an.icnsfile. If no output path is specified the app outputs tostdout.-png [<output path>]Outputs a.pngsequence as a.tarfile. If no output path is specified the app outputs tostdout.-h,--helpHelp.-v,--versionDisplay version information.
Examples
Let's say you have the following files saved at your file system.

We'll walk trought some practical examples of IconPie usage.
Simple Usage
Take
big.svg, resize it to 32x32, 64x64 and 128x128. Then save it aticon.ico.
$ icon-pie -e big.svg 32 64 128 -ico icon.ico

Sampling From Multiple Files
Take
small.png, resize it to 32x32 and 64x64. Then takebig.svgand resize it 128x128. Then combine the re-scaled entries inicon.icns.
$ icon-pie -e small.png 32 64 -e big.svg 128 -icns icon.icns

Specifying a Resampling Filter
Take
small.png, resize it to 32x32 and 64x64 using linear interpolation. Then takebig.svgand resize it 128x128. Then combine the re-scaled entries inicon.taras apngsequence.
$ icon-pie -e small.png 32 64 -r linear -e big.svg 128 -png icon.tar

Support
Icon Formats
This are the file formats IconPie can output to:
icoicnspngsequence (tar)
Icns Support
| OSType | Description | Supported? |
|---|---|---|
ICON |
32×32 1-bit entry | No |
ICN# |
32×32 1-bit entry with 1-bit mask | No |
icm# |
16×12 1-bit entry with 1-bit mask | No |
icm4 |
16×12 4-bit entry | No |
icm8 |
16×12 8-bit entry | No |
ics# |
16×16 1-bit mask | No |
ics4 |
16×16 4-bit entry | No |
ics8 |
16x16 8-bit entry | No |
is32 |
16×16 24-bit entry | Yes |
s8mk |
16x16 8-bit mask | Yes |
icl4 |
32×32 4-bit entry | No |
icl8 |
32×32 8-bit entry | No |
il32 |
32x32 24-bit entry | Yes |
l8mk |
32×32 8-bit mask | Yes |
ich# |
48×48 1-bit mask | No |
ich4 |
48×48 4-bit entry | No |
ich8 |
48×48 8-bit entry | No |
ih32 |
48×48 24-bit entry | Yes |
h8mk |
48×48 8-bit mask | Yes |
it32 |
128×128 24-bit entry | Yes |
t8mk |
128×128 8-bit mask | Yes |
icp4 |
16x16 32-bit png/jp2 entry |
png only |
icp5 |
32x32 32-bit png/jp2 entry |
png only |
icp6 |
64x64 32-bit png/jp2 entry |
png only |
ic07 |
128x128 32-bit png/jp2 entry |
png only |
ic08 |
256×256 32-bit png/jp2 entry |
png only |
ic09 |
512×512 32-bit png/jp2 entry |
png only |
ic10 |
512x512@2x "retina" 32-bit png/jp2 entry |
png only |
ic11 |
16x16@2x "retina" 32-bit png/jp2 entry |
png only |
ic12 |
32x32@2x "retina" 32-bit png/jp2 entry |
png only |
ic13 |
128x128@2x "retina" 32-bit png/jp2 entry |
png only |
ic14 |
256x256@2x "retina" 32-bit png/jp2 entry |
png only |
Image Formats
This are the formats IconPie can use as input:
| Format | Supported? |
|---|---|
png |
All supported color types |
jpeg |
Baseline and progressive |
gif |
Yes |
bmp |
Yes |
ico |
Yes |
tiff |
Baseline(no fax support), lzw, PackBits |
webp |
Lossy(Luma channel only) |
pnm |
pbm, pgm, ppm, standard pma |
svg |
Limited |
Svg Support
IconPie uses the nsvg crate to rasterize svg files.
According to the authors of the crate:
Like NanoSVG, the rasterizer only renders flat filled shapes. It is not particularly fast or accurate, but it is a simple way to bake vector graphics into textures.
The author of icon-pie is inclined to search for alternatives to nsvg if inquired to.
Help would be appreciated.
License
Licensed under MIT license(LICENSE-MIT or http://opensource.org/licenses/MIT).
Contribution
Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you shall be licensed as above, without any additional terms or conditions.