/**
* Saves an image as a png. This will overwrite an existing file.
*
* @param bi
* @param transparent the color to be made transparent (or null if none)
* @param outputStream (it is flushed at the end)
* @throws Exception if trouble
*/
public static void saveAsTransparentPng(
BufferedImage bi, Color transparent, OutputStream outputStream) throws Exception {
// convert transparent color to be transparent
long time = System.currentTimeMillis();
if (transparent != null) {
Image image = Image2.makeImageBackgroundTransparent(bi, transparent, 10000);
// convert image back to bufferedImage
bi = new BufferedImage(bi.getWidth(), bi.getHeight(), BufferedImage.TYPE_INT_ARGB);
Graphics g = bi.getGraphics();
g.drawImage(image, 0, 0, bi.getWidth(), bi.getHeight(), null);
}
// save as png
ImageIO.write(bi, "png", outputStream);
outputStream.flush();
if (verbose)
String2.log("SgtUtil.saveAsPng TIME=" + (System.currentTimeMillis() - time) + "\n");
}
/**
* Saves an image as a gif. Currently this uses ImageMagick's "convert" (Windows or Linux) because
* it does the best job at color reduction (and is fast and is cross-platform). This will
* overwrite an existing file.
*
* @param bi
* @param transparent the color to be made transparent
* @param fullGifName but without the .gif at the end
* @throws Exception if trouble
*/
public static void saveAsTransparentGif(BufferedImage bi, Color transparent, String fullGifName)
throws Exception {
// POLICY: because this procedure may be used in more than one thread,
// do work on unique temp files names using randomInt, then rename to proper file name.
// If procedure fails half way through, there won't be a half-finished file.
int randomInt = Math2.random(Integer.MAX_VALUE);
// convert transparent color to be transparent
long time = System.currentTimeMillis();
Image image = Image2.makeImageBackgroundTransparent(bi, transparent, 10000);
// convert image back to bufferedImage
bi = new BufferedImage(bi.getWidth(), bi.getHeight(), BufferedImage.TYPE_INT_ARGB);
Graphics g = bi.getGraphics();
g.drawImage(image, 0, 0, bi.getWidth(), bi.getHeight(), null);
image = null; // encourage garbage collection
// save as png
int random = Math2.random(Integer.MAX_VALUE);
ImageIO.write(bi, "png", new File(fullGifName + randomInt + ".png"));
// "convert" to .gif
SSR.dosOrCShell(
"convert " + fullGifName + randomInt + ".png" + " " + fullGifName + randomInt + ".gif", 30);
File2.delete(fullGifName + randomInt + ".png");
// try fancy color reduction algorithms
// Image2.saveAsGif(Image2.reduceTo216Colors(bi), fullGifName + randomInt + ".gif");
// try dithering
// Image2.saveAsGif216(bi, fullGifName + randomInt + ".gif", true);
// last step: rename to final gif name
File2.rename(fullGifName + randomInt + ".gif", fullGifName + ".gif");
if (verbose)
String2.log(
"SgtUtil.saveAsTransparentGif TIME=" + (System.currentTimeMillis() - time) + "\n");
}