Example usage for org.apache.pdfbox.cos COSName PREDICTOR

Introduction

In this page you can find the example usage for org.apache.pdfbox.cos COSName PREDICTOR.

Prototype

COSName PREDICTOR

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Usage

From source file:pdfpicmangler.PDPng.java

License:Open Source License

/**
 * Construct from a stream./*from  w ww.j av  a  2s .  c  o m*/
 * 
 * @param doc The document to create the image as part of.
 * @param is The stream that contains the png data.
 * @throws IOException If there is an error reading the png data.
 */
public PDPng(PDDocument doc, InputStream is) throws IOException {
    super(doc, "png");

    System.out.println("reading in png");

    COSDictionary dic = getCOSStream();

    dic.setItem(COSName.SUBTYPE, COSName.IMAGE);
    //dic.setItem(COSName.TYPE, COSName.XOBJECT);

    data = getCOSStream().createFilteredStream();

    readPng(is);

    setWidth(imageWidth);
    setHeight(imageHeight);
    dic.setInt(COSName.BITS_PER_COMPONENT, bitDepth);

    if ((colorType & PNG_TYPE_PALETTE) != 0) {
        getCOSStream().setItem(COSName.COLORSPACE, paldata);
    } else if ((colorType & PNG_TYPE_COLOR) != 0) {
        setColorSpace(PDDeviceRGB.INSTANCE);
    } else {
        setColorSpace(new PDDeviceGray());
    }

    COSDictionary filterParams = new COSDictionary();
    filterParams.setInt(COSName.PREDICTOR, 15); // png adaptive predictor
    filterParams.setInt(COSName.COLORS,
            ((colorType & PNG_TYPE_COLOR) == 0 || (colorType & PNG_TYPE_PALETTE) != 0) ? 1 : 3);
    filterParams.setInt(COSName.BITS_PER_COMPONENT, bitDepth);
    filterParams.setInt(COSName.COLUMNS, imageWidth);
    filterParams.setDirect(true);

    dic.setItem(COSName.DECODE_PARMS, filterParams);
    dic.setItem(COSName.FILTER, COSName.FLATE_DECODE);

    dic.setInt(COSName.LENGTH, dataLen);
    dic.getDictionaryObject(COSName.LENGTH).setDirect(true);
}

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