TGA (AKA Truevision TGA, AKA TARGA) raster image file format: Python parsing library

TGA (AKA Truevision TGA, AKA TARGA), is a raster image file format created by Truevision. It supports up to 32 bits per pixel (three 8-bit RGB channels + 8-bit alpha channel), color mapping and optional lossless RLE compression.

File extension

["tga", "icb", "vda", "vst"]

KS implementation details

License: CC0-1.0

References

This page hosts a formal specification of TGA (AKA Truevision TGA, AKA TARGA) raster image file format using Kaitai Struct. This specification can be automatically translated into a variety of programming languages to get a parsing library.

Usage

Runtime 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 kaitaistruct

Code

Parse a local file and get structure in memory:

data = Tga.from_file("path/to/local/file.["tga", "icb", "vda", "vst"]")

Or parse structure from a bytes:

from kaitaistruct import KaitaiStream, BytesIO

raw = b"\x00\x01\x02..."
data = Tga(KaitaiStream(BytesIO(raw)))

After that, one can get various attributes from the structure by invoking getter methods like:

data.num_color_map # => Number of entries in a color map

Python source code to parse TGA (AKA Truevision TGA, AKA TARGA) raster image file format

tga.py

# This is a generated file! Please edit source .ksy file and use kaitai-struct-compiler to rebuild

from pkg_resources import parse_version
import kaitaistruct
from kaitaistruct import KaitaiStruct, KaitaiStream, BytesIO
from enum import Enum


if parse_version(kaitaistruct.__version__) < parse_version('0.9'):
    raise Exception("Incompatible Kaitai Struct Python API: 0.9 or later is required, but you have %s" % (kaitaistruct.__version__))

class Tga(KaitaiStruct):
    """TGA (AKA Truevision TGA, AKA TARGA), is a raster image file format created by Truevision. It supports up to 32 bits per pixel (three 8-bit RGB channels + 8-bit alpha channel), color mapping and optional lossless RLE compression.
    
    .. seealso::
       Source - http://www.dca.fee.unicamp.br/~martino/disciplinas/ea978/tgaffs.pdf
    """

    class ColorMapEnum(Enum):
        no_color_map = 0
        has_color_map = 1

    class ImageTypeEnum(Enum):
        no_image_data = 0
        uncomp_color_mapped = 1
        uncomp_true_color = 2
        uncomp_bw = 3
        rle_color_mapped = 9
        rle_true_color = 10
        rle_bw = 11
    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.image_id_len = self._io.read_u1()
        self.color_map_type = KaitaiStream.resolve_enum(Tga.ColorMapEnum, self._io.read_u1())
        self.image_type = KaitaiStream.resolve_enum(Tga.ImageTypeEnum, self._io.read_u1())
        self.color_map_ofs = self._io.read_u2le()
        self.num_color_map = self._io.read_u2le()
        self.color_map_depth = self._io.read_u1()
        self.x_offset = self._io.read_u2le()
        self.y_offset = self._io.read_u2le()
        self.width = self._io.read_u2le()
        self.height = self._io.read_u2le()
        self.image_depth = self._io.read_u1()
        self.img_descriptor = self._io.read_u1()
        self.image_id = self._io.read_bytes(self.image_id_len)
        if self.color_map_type == Tga.ColorMapEnum.has_color_map:
            self.color_map = [None] * (self.num_color_map)
            for i in range(self.num_color_map):
                self.color_map[i] = self._io.read_bytes((self.color_map_depth + 7) // 8)



    class TgaFooter(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.ext_area_ofs = self._io.read_u4le()
            self.dev_dir_ofs = self._io.read_u4le()
            self.version_magic = self._io.read_bytes(18)

        @property
        def is_valid(self):
            if hasattr(self, '_m_is_valid'):
                return self._m_is_valid if hasattr(self, '_m_is_valid') else None

            self._m_is_valid = self.version_magic == b"\x54\x52\x55\x45\x56\x49\x53\x49\x4F\x4E\x2D\x58\x46\x49\x4C\x45\x2E\x00"
            return self._m_is_valid if hasattr(self, '_m_is_valid') else None

        @property
        def ext_area(self):
            if hasattr(self, '_m_ext_area'):
                return self._m_ext_area if hasattr(self, '_m_ext_area') else None

            if self.is_valid:
                _pos = self._io.pos()
                self._io.seek(self.ext_area_ofs)
                self._m_ext_area = Tga.TgaExtArea(self._io, self, self._root)
                self._io.seek(_pos)

            return self._m_ext_area if hasattr(self, '_m_ext_area') else None


    class TgaExtArea(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.ext_area_size = self._io.read_u2le()
            self.author_name = (self._io.read_bytes(41)).decode(u"ASCII")
            self.comments = [None] * (4)
            for i in range(4):
                self.comments[i] = (self._io.read_bytes(81)).decode(u"ASCII")

            self.timestamp = self._io.read_bytes(12)
            self.job_id = (self._io.read_bytes(41)).decode(u"ASCII")
            self.job_time = (self._io.read_bytes(6)).decode(u"ASCII")
            self.software_id = (self._io.read_bytes(41)).decode(u"ASCII")
            self.software_version = self._io.read_bytes(3)
            self.key_color = self._io.read_u4le()
            self.pixel_aspect_ratio = self._io.read_u4le()
            self.gamma_value = self._io.read_u4le()
            self.color_corr_ofs = self._io.read_u4le()
            self.postage_stamp_ofs = self._io.read_u4le()
            self.scan_line_ofs = self._io.read_u4le()
            self.attributes = self._io.read_u1()


    @property
    def footer(self):
        if hasattr(self, '_m_footer'):
            return self._m_footer if hasattr(self, '_m_footer') else None

        _pos = self._io.pos()
        self._io.seek((self._io.size() - 26))
        self._m_footer = Tga.TgaFooter(self._io, self, self._root)
        self._io.seek(_pos)
        return self._m_footer if hasattr(self, '_m_footer') else None