Microsoft Windows uses specific file format to store applications icons - ICO. This is a container that contains one or more image files (effectively, DIB parts of BMP files or full PNG files are contained inside).
This page hosts a formal specification of Microsoft Windows icon file using Kaitai Struct. This specification can be automatically translated into a variety of programming languages to get a parsing library.
All parsing code for Python generated by Kaitai Struct depends on the Python runtime library. You have to install it before you can parse data.
The Python runtime library can be installed from PyPI:
python3 -m pip install kaitaistructParse a local file and get structure in memory:
data = Ico.from_file("path/to/local/file.ico")
Or parse structure from a bytes:
from kaitaistruct import KaitaiStream, BytesIO
raw = b"\x00\x01\x02..."
data = Ico(KaitaiStream(BytesIO(raw)))
After that, one can get various attributes from the structure by invoking getter methods like:
data.num_images # => Number of images contained in this file
# This is a generated file! Please edit source .ksy file and use kaitai-struct-compiler to rebuild
import kaitaistruct
from kaitaistruct import KaitaiStruct, KaitaiStream, BytesIO
if getattr(kaitaistruct, 'API_VERSION', (0, 9)) < (0, 9):
raise Exception("Incompatible Kaitai Struct Python API: 0.9 or later is required, but you have %s" % (kaitaistruct.__version__))
class Ico(KaitaiStruct):
"""Microsoft Windows uses specific file format to store applications
icons - ICO. This is a container that contains one or more image
files (effectively, DIB parts of BMP files or full PNG files are
contained inside).
.. seealso::
Source - https://learn.microsoft.com/en-us/previous-versions/ms997538(v=msdn.10)
"""
def __init__(self, _io, _parent=None, _root=None):
self._io = _io
self._parent = _parent
self._root = _root if _root else self
self._read()
def _read(self):
self.magic = self._io.read_bytes(4)
if not self.magic == b"\x00\x00\x01\x00":
raise kaitaistruct.ValidationNotEqualError(b"\x00\x00\x01\x00", self.magic, self._io, u"/seq/0")
self.num_images = self._io.read_u2le()
self.images = []
for i in range(self.num_images):
self.images.append(Ico.IconDirEntry(self._io, self, self._root))
class IconDirEntry(KaitaiStruct):
def __init__(self, _io, _parent=None, _root=None):
self._io = _io
self._parent = _parent
self._root = _root if _root else self
self._read()
def _read(self):
self.width = self._io.read_u1()
self.height = self._io.read_u1()
self.num_colors = self._io.read_u1()
self.reserved = self._io.read_bytes(1)
if not self.reserved == b"\x00":
raise kaitaistruct.ValidationNotEqualError(b"\x00", self.reserved, self._io, u"/types/icon_dir_entry/seq/3")
self.num_planes = self._io.read_u2le()
self.bpp = self._io.read_u2le()
self.len_img = self._io.read_u4le()
self.ofs_img = self._io.read_u4le()
@property
def img(self):
"""Raw image data. Use `is_png` to determine whether this is an
embedded PNG file (true) or a DIB bitmap (false) and call a
relevant parser, if needed to parse image data further.
"""
if hasattr(self, '_m_img'):
return self._m_img
_pos = self._io.pos()
self._io.seek(self.ofs_img)
self._m_img = self._io.read_bytes(self.len_img)
self._io.seek(_pos)
return getattr(self, '_m_img', None)
@property
def png_header(self):
"""Pre-reads first 8 bytes of the image to determine if it's an
embedded PNG file.
"""
if hasattr(self, '_m_png_header'):
return self._m_png_header
_pos = self._io.pos()
self._io.seek(self.ofs_img)
self._m_png_header = self._io.read_bytes(8)
self._io.seek(_pos)
return getattr(self, '_m_png_header', None)
@property
def is_png(self):
"""True if this image is in PNG format."""
if hasattr(self, '_m_is_png'):
return self._m_is_png
self._m_is_png = self.png_header == b"\x89\x50\x4E\x47\x0D\x0A\x1A\x0A"
return getattr(self, '_m_is_png', None)