xwd is a file format written by eponymous X11 screen capture
application (xwd stands for "X Window Dump"). Typically, an average
user transforms xwd format into something more widespread by any of
xwdtopnm and pnmto... utilities right away.
xwd format itself provides a raw uncompressed bitmap with some metainformation, like pixel format, width, height, bit depth, etc. Note that technically format includes machine-dependent fields and thus is probably a poor choice for true cross-platform usage.
This page hosts a formal specification of xwd (X Window Dump) bitmap image 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 = Xwd.from_file("path/to/local/file.xwd")
Or parse structure from a bytes:
from kaitaistruct import KaitaiStream, BytesIO
raw = b"\x00\x01\x02..."
data = Xwd(KaitaiStream(BytesIO(raw)))
After that, one can get various attributes from the structure by invoking getter methods like:
data.len_header # => Size of the header in bytes
# 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
from enum import Enum
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 Xwd(KaitaiStruct):
"""xwd is a file format written by eponymous X11 screen capture
application (xwd stands for "X Window Dump"). Typically, an average
user transforms xwd format into something more widespread by any of
`xwdtopnm` and `pnmto...` utilities right away.
xwd format itself provides a raw uncompressed bitmap with some
metainformation, like pixel format, width, height, bit depth,
etc. Note that technically format includes machine-dependent fields
and thus is probably a poor choice for true cross-platform usage.
"""
class PixmapFormat(Enum):
x_y_bitmap = 0
x_y_pixmap = 1
z_pixmap = 2
class ByteOrder(Enum):
le = 0
be = 1
class VisualClass(Enum):
static_gray = 0
gray_scale = 1
static_color = 2
pseudo_color = 3
true_color = 4
direct_color = 5
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.len_header = self._io.read_u4be()
self._raw_hdr = self._io.read_bytes((self.len_header - 4))
_io__raw_hdr = KaitaiStream(BytesIO(self._raw_hdr))
self.hdr = Xwd.Header(_io__raw_hdr, self, self._root)
self._raw_color_map = []
self.color_map = []
for i in range(self.hdr.color_map_entries):
self._raw_color_map.append(self._io.read_bytes(12))
_io__raw_color_map = KaitaiStream(BytesIO(self._raw_color_map[i]))
self.color_map.append(Xwd.ColorMapEntry(_io__raw_color_map, self, self._root))
class Header(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.file_version = self._io.read_u4be()
self.pixmap_format = KaitaiStream.resolve_enum(Xwd.PixmapFormat, self._io.read_u4be())
self.pixmap_depth = self._io.read_u4be()
self.pixmap_width = self._io.read_u4be()
self.pixmap_height = self._io.read_u4be()
self.x_offset = self._io.read_u4be()
self.byte_order = KaitaiStream.resolve_enum(Xwd.ByteOrder, self._io.read_u4be())
self.bitmap_unit = self._io.read_u4be()
self.bitmap_bit_order = self._io.read_u4be()
self.bitmap_pad = self._io.read_u4be()
self.bits_per_pixel = self._io.read_u4be()
self.bytes_per_line = self._io.read_u4be()
self.visual_class = KaitaiStream.resolve_enum(Xwd.VisualClass, self._io.read_u4be())
self.red_mask = self._io.read_u4be()
self.green_mask = self._io.read_u4be()
self.blue_mask = self._io.read_u4be()
self.bits_per_rgb = self._io.read_u4be()
self.number_of_colors = self._io.read_u4be()
self.color_map_entries = self._io.read_u4be()
self.window_width = self._io.read_u4be()
self.window_height = self._io.read_u4be()
self.window_x = self._io.read_s4be()
self.window_y = self._io.read_s4be()
self.window_border_width = self._io.read_u4be()
self.creator = (self._io.read_bytes_term(0, False, True, True)).decode(u"UTF-8")
class ColorMapEntry(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.entry_number = self._io.read_u4be()
self.red = self._io.read_u2be()
self.green = self._io.read_u2be()
self.blue = self._io.read_u2be()
self.flags = self._io.read_u1()
self.padding = self._io.read_u1()