Programmatically Reducing JPEG file size

Question

Apologies for any ignorance, but I have never worked with jpeg images (let alone any types of images) in Java before.

Supposing I want to send a jpeg image from a we

Answer 1

Another way to reduce image size is to change compression level. You can do that using ImageWriter.

    ImageWriter writer = null;
    Iterator iwi = ImageIO.getImageWritersByFormatName("jpg");
    if (!iwi.hasNext())
        return;
    writer = (ImageWriter) iwi.next();
    ImageWriteParam iwp = writer.getDefaultWriteParam();
    iwp.setCompressionMode(ImageWriteParam.MODE_EXPLICIT) ;
    iwp.setCompressionQuality(compressionQuality);
    writer.setOutput(...);
    writer.write(null, image, iwp);