Examples with ChunksListForWrite ar.com.hjg.pngj.chunks.ChunksListForWrite used on opensource projects

Example 1 with ChunksListForWrite

use of ar.com.hjg.pngj.chunks.ChunksListForWrite in project imageio-ext by geosolutions-it.

the class PNGWriter method writePNG.

public RenderedImage writePNG(RenderedImage image, OutputStream outStream, float quality, FilterType filterType, Map<String, String> text) throws Exception {
    // compute the compression level similarly to what the Clib code does
    int level = Math.round(9 * (1f - quality));
    // get the optimal scanline provider for this image
    RenderedImage original = image;
    ScanlineProvider scanlines = ScanlineProviderFactory.getProvider(image);
    if (scanlines == null) {
        throw new IllegalArgumentException("Could not find a scanline extractor for " + original);
    }
    // encode using the PNGJ library and the GeoServer own scanline providers
    ColorModel colorModel = image.getColorModel();
    boolean indexed = colorModel instanceof IndexColorModel;
    ImageInfo ii = getImageInfo(image, scanlines, colorModel, indexed);
    PngWriter pw = new PngWriter(outStream, ii);
    pw.setShouldCloseStream(false);
    try {
        pw.setCompLevel(level);
        pw.setFilterType(filterType);
        ChunksListForWrite chunkList = pw.getChunksList();
        PngMetadata metadata = pw.getMetadata();
        if (indexed) {
            IndexColorModel icm = (IndexColorModel) colorModel;
            PngChunkPLTE palette = metadata.createPLTEChunk();
            int ncolors = icm.getMapSize();
            palette.setNentries(ncolors);
            for (int i = 0; i < ncolors; i++) {
                final int red = icm.getRed(i);
                final int green = icm.getGreen(i);
                final int blue = icm.getBlue(i);
                palette.setEntry(i, red, green, blue);
            }
            if (icm.hasAlpha()) {
                PngChunkTRNS transparent = new PngChunkTRNS(ii);
                int[] alpha = new int[ncolors];
                for (int i = 0; i < ncolors; i++) {
                    final int a = icm.getAlpha(i);
                    alpha[i] = a;
                }
                transparent.setPalletteAlpha(alpha);
                chunkList.queue(transparent);
            }
        }
        if (text != null && !text.isEmpty()) {
            Iterator<Entry<String, String>> entrySetIterator = text.entrySet().iterator();
            while (entrySetIterator.hasNext()) {
                Entry<String, String> entrySet = entrySetIterator.next();
                metadata.setText(entrySet.getKey(), entrySet.getValue(), true, false);
            }
        }
        // write out the actual image lines
        for (int row = 0; row < image.getHeight(); row++) {
            pw.writeRow(scanlines);
        }
        pw.end();
    } catch (Exception e) {
        LOGGER.log(Level.SEVERE, "Failed to encode the PNG", e);
        throw e;
    } finally {
        pw.close();
    }
    return image;
}