Source code for psd_tools.psd.image_data

"""
Image data section structure.
"""
from __future__ import absolute_import, unicode_literals
import attr
import logging
import io

from psd_tools.compression import compress, decompress
from psd_tools.constants import Compression
from psd_tools.psd.base import BaseElement
from psd_tools.validators import in_
from psd_tools.utils import read_fmt, write_fmt, write_bytes, pack

logger = logging.getLogger(__name__)


[docs]@attr.s(slots=True) class ImageData(BaseElement): """ Merged channel image data. .. py:attribute:: compression See :py:class:`~psd_tools.constants.Compression`. .. py:attribute:: data """ compression = attr.ib(default=Compression.RAW, converter=Compression, validator=in_(Compression)) data = attr.ib(default=b'', type=bytes, repr=False)
[docs] @classmethod def read(cls, fp): """Read the element from a file-like object. :param fp: file-like object :rtype: :py:class:`.ImageData` """ start_pos = fp.tell() compression = Compression(read_fmt('H', fp)[0]) data = fp.read() # TODO: Parse data here. Need header. logger.debug(' read image data, len=%d' % (fp.tell() - start_pos)) return cls(compression, data)
[docs] def write(self, fp): """Write the element to a file-like object. :param fp: file-like object :rtype: int """ start_pos = fp.tell() written = write_fmt(fp, 'H', self.compression.value) written += write_bytes(fp, self.data) logger.debug(' wrote image data, len=%d' % (fp.tell() - start_pos)) return written
[docs] def get_data(self, header): """Get decompressed data. :param header: See :py:class:`~psd_tools.psd.header.FileHeader`. :return: list of bytes corresponding each channel. :rtype: list """ data = decompress(self.data, self.compression, header.width, header.height * header.channels, header.depth, header.version) plane_size = len(data) // header.channels with io.BytesIO(data) as f: return [f.read(plane_size) for _ in range(header.channels)]
[docs] def set_data(self, data, header): """Set raw data and compress. :param data: list of raw data bytes corresponding channels. :param compression: compression type, see :py:class:`~psd_tools.constants.Compression`. :param header: See :py:class:`~psd_tools.psd.header.FileHeader`. :return: length of compressed data. """ self.data = compress(b''.join(data), self.compression, header.width, header.height * header.channels, header.depth, header.version) return len(self.data)
[docs] @classmethod def new(cls, header, color=0, compression=Compression.RAW): """Create a new image data object. :param header: FileHeader. :param compression: compression type. :param color: default color. int or iterable for channel length. """ plane_size = header.width * header.height if isinstance(color, (bool, int, float)): color = (color,) * header.channels if len(color) != header.channels: raise ValueError('Invalid color %s for channel size %d' % ( color, header.channels) ) # Bitmap is not supported here. fmt = {8: 'B', 16: 'H', 32: 'I'}.get(header.depth) data = [] for i in range(header.channels): data.append(pack(fmt, color[i]) * plane_size) self = cls(compression=compression) self.set_data(data, header) return self