image.dart
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/*
* Copyright (C) 2017, David PHAM-VAN <dev.nfet.net@gmail.com>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General License for more details.
*
* You should have received a copy of the GNU Lesser General
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
part of pdf;
class PDFImage extends PDFXObject {
final Image _img;
String _name;
final bool _alphaChannel;
/// Creates a new <code>PDFImage</code> instance.
///
/// @param img an <code>Image</code> value
/// @param x an <code>int</code> value
/// @param y an <code>int</code> value
/// @param w an <code>int</code> value
/// @param h an <code>int</code> value
/// @param obs an <code>ImageObserver</code> value
PDFImage(PDFDocument pdfDocument, this._img, [this._alphaChannel = false]) : super(pdfDocument, "/Image", isBinary: true) {
_name = "/Image$objser";
params["/Width"] = PDFStream.string(_img.width.toString());
params["/Height"] = PDFStream.string(_img.height.toString());
params["/BitsPerComponent"] = PDFStream.intNum(8);
params['/Name'] = PDFStream.string(_name);
if (_alphaChannel == false && _img.numChannels == 4) {
var _sMask = new PDFImage(pdfDocument, this._img, true);
params["/SMask"] = PDFStream.string("${_sMask.objser} 0 R");
}
if (_alphaChannel) {
params["/ColorSpace"] = PDFStream.string("/DeviceGray");
} else {
params["/ColorSpace"] = PDFStream.string("/DeviceRGB");
}
// write the pixels to the stream
// print("Processing image ${img.width}x${img.height} pixels");
int w = _img.width;
int h = _img.height;
int s = w * h;
Uint8List out = new Uint8List(_alphaChannel ? s : s * 3);
if (_alphaChannel) {
for (int i = 0; i < s; i++) {
final p = _img.data[i];
final int alpha = (p >> 24) & 0xff;
out[i] = alpha;
}
} else {
for (int i = 0; i < s; i++) {
final p = _img.data[i];
final int blue = (p >> 16) & 0xff;
final int green = (p >> 8) & 0xff;
final int red = p & 0xff;
out[i * 3] = red;
out[i * 3 + 1] = green;
out[i * 3 + 2] = blue;
}
}
buf.putBytes(out);
}
/// Get the value of width.
/// @return value of width.
int get width => _img.width;
/// Get the value of height.
/// @return value of height.
int get height => _img.height;
/// Get the name
///
/// @return a <code>String</code> value
String get name => _name;
}