使用 Java 进行图像转码（JPEG 到 PNG）
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Image transcoding (JPEG to PNG) with Java
提问by adam
In my Java application I would like to download a JPEG, transfer it to a PNG and do something with the resulting bytes.
在我的 Java 应用程序中，我想下载一个 JPEG，将它传输到一个 PNG 并使用结果字节做一些事情。
I am almost certain I remember a library to do this exists, I cannot remember its name.
我几乎可以肯定我记得有一个图书馆可以做到这一点，我不记得它的名字了。
采纳答案by Joachim Sauer
回答by bezmax
javax.imageioshould be enough. Put your JPEG to BufferedImage, then save it with:
javax.imageio应该足够了。将您的 JPEG 放入 BufferedImage，然后将其保存为：
File file = new File("newimage.png");
ImageIO.write(myJpegImage, "png", file);
回答by adam
This is what I ended up doing, I was thinking toooo far outside of the box when I asked the question..
这就是我最终要做的，当我问这个问题时，我想得太远了。
// these are the imports needed
import java.awt.image.BufferedImage;
import java.io.File;
import javax.imageio.ImageIO;
import java.io.ByteArrayOutputStream;
// read a jpeg from a inputFile
BufferedImage bufferedImage = ImageIO.read(new File(inputFile));
// write the bufferedImage back to outputFile
ImageIO.write(bufferedImage, "png", new File(outputFile));
// this writes the bufferedImage into a byte array called resultingBytes
ByteArrayOutputStream byteArrayOut = new ByteArrayOutputStream();
ImageIO.write(bufferedImage, "png", byteArrayOut);
byte[] resultingBytes = byteArrayOut.toByteArray();
回答by waviq
BufferedImage bufferGambar;
try {
bufferGambar = ImageIO.read(new File("ImagePNG.png"));
// pkai type INT karna bertipe integer RGB bufferimage
BufferedImage newBufferGambar = new BufferedImage(bufferGambar.getWidth(), bufferGambar.getHeight(), BufferedImage.TYPE_INT_RGB);
newBufferGambar.createGraphics().drawImage(bufferGambar, 0, 0, Color.white, null);
ImageIO.write(newBufferGambar, "jpg", new File("Create file JPEG.jpg"));
JOptionPane.showMessageDialog(null, "Convert to JPG succes YES");
} catch(Exception e) {
JOptionPane.showMessageDialog(null, e);
}
