Method saveImageIO

core/src/processing/awt/ShimAWT.java:553–631

Use ImageIO functions from Java 1.4 and later to handle image save. Various formats are supported, typically jpeg, png, bmp, and wbmp. To get a list of the supported formats for writing, use: println(javax.imageio.ImageIO.getReaderFormatNames())

(PImage image, String path, String... args)

   * <TT>println(javax.imageio.ImageIO.getReaderFormatNames())</TT>
   */
  static protected boolean saveImageIO(PImage image, String path, String... args) throws IOException {
    try {
      int outputFormat = (image.format == ARGB) ?
        BufferedImage.TYPE_INT_ARGB : BufferedImage.TYPE_INT_RGB;

      Map<String, Number> params = new HashMap<>();
      params.put("quality", 0.9f);  // default JPEG quality
      params.put("dpi", 100.0);  // default DPI for PNG

      if (args != null) {
        for (String arg : args) {
          if (arg.startsWith("quality=")) {
            params.put("quality", Float.parseFloat(arg.substring(8)));
          } else if (arg.startsWith("dpi=")) {
            params.put("dpi", Double.parseDouble(arg.substring(4)));
          }
        }
      }

      String extension =
        path.substring(path.lastIndexOf('.') + 1).toLowerCase();

      // JPEG and BMP images that have an alpha channel set get pretty unhappy.
      // BMP just doesn't write, and JPEG writes it as a CMYK image.
      // https://github.com/processing/processing/issues/454
      if (extension.equals("bmp") || extension.equals("jpg") || extension.equals("jpeg")) {
        outputFormat = BufferedImage.TYPE_INT_RGB;
      }

      BufferedImage bimage = new BufferedImage(image.pixelWidth, image.pixelHeight, outputFormat);
      bimage.setRGB(0, 0, image.pixelWidth, image.pixelHeight, image.pixels, 0, image.pixelWidth);

      File file = new File(path);

      ImageWriter writer = null;
      ImageWriteParam param = null;
      IIOMetadata metadata = null;

      if (extension.equals("jpg") || extension.equals("jpeg")) {
        if ((writer = imageioWriter("jpeg")) != null) {
          // Set JPEG quality to 90% with baseline optimization. Setting this
          // to 1 was a huge jump (about triple the size), so this seems good.
          // Oddly, a smaller file size than Photoshop at 90%, but I suppose
          // it's a completely different algorithm.
          param = writer.getDefaultWriteParam();
          param.setCompressionMode(ImageWriteParam.MODE_EXPLICIT);
          //param.setCompressionQuality(0.9f);
          param.setCompressionQuality((Float) params.get("quality"));
        }
      }

      if (extension.equals("png")) {
        if ((writer = imageioWriter("png")) != null) {
          param = writer.getDefaultWriteParam();
          metadata = imageioDPI(writer, param, (Double) params.get("dpi"));
        }
      }