diff options
Diffstat (limited to 'silx/gui/plot/backends/glutils/PlotImageFile.py')
| -rw-r--r-- | silx/gui/plot/backends/glutils/PlotImageFile.py | 153 |
1 files changed, 153 insertions, 0 deletions
diff --git a/silx/gui/plot/backends/glutils/PlotImageFile.py b/silx/gui/plot/backends/glutils/PlotImageFile.py new file mode 100644 index 0000000..f028ee8 --- /dev/null +++ b/silx/gui/plot/backends/glutils/PlotImageFile.py @@ -0,0 +1,153 @@ +# coding: utf-8 +# /*########################################################################## +# +# Copyright (c) 2014-2017 European Synchrotron Radiation Facility +# +# Permission is hereby granted, free of charge, to any person obtaining a copy +# of this software and associated documentation files (the "Software"), to deal +# in the Software without restriction, including without limitation the rights +# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell +# copies of the Software, and to permit persons to whom the Software is +# furnished to do so, subject to the following conditions: +# +# The above copyright notice and this permission notice shall be included in +# all copies or substantial portions of the Software. +# +# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR +# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, +# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE +# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER +# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, +# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN +# THE SOFTWARE. +# +# ############################################################################*/ +"""Function to save an image to a file.""" + +__authors__ = ["T. Vincent"] +__license__ = "MIT" +__date__ = "03/04/2017" + + +import base64 +import struct +import sys +import zlib + + +# Image writer ################################################################ + +def convertRGBDataToPNG(data): + """Convert a RGB bitmap to PNG. + + It only supports RGB bitmap with one byte per channel stored as a 3D array. + See `Definitive Guide <http://www.libpng.org/pub/png/book/>`_ and + `Specification <http://www.libpng.org/pub/png/spec/1.2/>`_ for details. + + :param data: A 3D array (h, w, rgb) storing an RGB image + :type data: numpy.ndarray of unsigned bytes + :returns: The PNG encoded data + :rtype: bytes + """ + height, width = data.shape[0], data.shape[1] + depth = 8 # 8 bit per channel + colorType = 2 # 'truecolor' = RGB + interlace = 0 # No + + IHDRdata = struct.pack(">ccccIIBBBBB", b'I', b'H', b'D', b'R', + width, height, depth, colorType, + 0, 0, interlace) + + # Add filter 'None' before each scanline + preparedData = b'\x00' + b'\x00'.join(line.tostring() for line in data) + compressedData = zlib.compress(preparedData, 8) + + IDATdata = struct.pack("cccc", b'I', b'D', b'A', b'T') + IDATdata += compressedData + + return b''.join([ + b'\x89PNG\r\n\x1a\n', # PNG signature + # IHDR chunk: Image Header + struct.pack(">I", 13), # length + IHDRdata, + struct.pack(">I", zlib.crc32(IHDRdata) & 0xffffffff), # CRC + # IDAT chunk: Payload + struct.pack(">I", len(compressedData)), + IDATdata, + struct.pack(">I", zlib.crc32(IDATdata) & 0xffffffff), # CRC + b'\x00\x00\x00\x00IEND\xaeB`\x82' # IEND chunk: footer + ]) + + +def saveImageToFile(data, fileNameOrObj, fileFormat): + """Save a RGB image to a file. + + :param data: A 3D array (h, w, 3) storing an RGB image. + :type data: numpy.ndarray with of unsigned bytes. + :param fileNameOrObj: Filename or object to use to write the image. + :type fileNameOrObj: A str or a 'file-like' object with a 'write' method. + :param str fileFormat: The type of the file in: 'png', 'ppm', 'svg', 'tiff'. + """ + assert len(data.shape) == 3 + assert data.shape[2] == 3 + assert fileFormat in ('png', 'ppm', 'svg', 'tiff') + + if not hasattr(fileNameOrObj, 'write'): + if sys.version < "3.0": + fileObj = open(fileNameOrObj, "wb") + else: + if fileFormat in ('png', 'ppm', 'tiff'): + # Open in binary mode + fileObj = open(fileNameOrObj, 'wb') + else: + fileObj = open(fileNameOrObj, 'w', newline='') + else: # Use as a file-like object + fileObj = fileNameOrObj + + if fileFormat == 'svg': + height, width = data.shape[:2] + base64Data = base64.b64encode(convertRGBDataToPNG(data)) + + fileObj.write( + '<?xml version="1.0" encoding="UTF-8" standalone="no"?>\n') + fileObj.write('<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN"\n') + fileObj.write( + ' "http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">\n') + fileObj.write('<svg xmlns:xlink="http://www.w3.org/1999/xlink"\n') + fileObj.write(' xmlns="http://www.w3.org/2000/svg"\n') + fileObj.write(' version="1.1"\n') + fileObj.write(' width="%d"\n' % width) + fileObj.write(' height="%d">\n' % height) + fileObj.write(' <image xlink:href="data:image/png;base64,') + fileObj.write(base64Data.decode('ascii')) + fileObj.write('"\n') + fileObj.write(' x="0"\n') + fileObj.write(' y="0"\n') + fileObj.write(' width="%d"\n' % width) + fileObj.write(' height="%d"\n' % height) + fileObj.write(' id="image" />\n') + fileObj.write('</svg>') + + elif fileFormat == 'ppm': + height, width = data.shape[:2] + + fileObj.write(b'P6\n') + fileObj.write(b'%d %d\n' % (width, height)) + fileObj.write(b'255\n') + fileObj.write(data.tostring()) + + elif fileFormat == 'png': + fileObj.write(convertRGBDataToPNG(data)) + + elif fileFormat == 'tiff': + if fileObj == fileNameOrObj: + raise NotImplementedError( + 'Save TIFF to a file-like object not implemented') + + from silx.third_party.TiffIO import TiffIO + + tif = TiffIO(fileNameOrObj, mode='wb+') + tif.writeImage(data, info={'Title': 'OpenGL Plot Snapshot'}) + + if fileObj != fileNameOrObj: + fileObj.close() |