java - 将图像复制到不同大小的另一个位置

Question

我正在尝试使用 Java 将图像文件从一个位置复制到另一个位置。现在我想将图像文件保存为特定大小，无论源位置中图像文件的大小是多少。

我正在使用以下代码，它在目标位置生成与源文件大小相同的图像：

public class filecopy {
    public static void copyFile(File sourceFile, File destFile)
            throws IOException {
        if (!destFile.exists()) {
            destFile.createNewFile();
        }

        FileChannel source = null;
        FileChannel destination = null;
        try {
            source = new FileInputStream(sourceFile).getChannel();
            destination = new FileOutputStream(destFile).getChannel();

            // previous code: destination.transferFrom(source, 0, source.size());
            // to avoid infinite loops, should be:
            long count = 0;
            long size = source.size();
            while ((count += destination.transferFrom(source, count, size
                    - count)) < size)
                ;
        } finally {
            if (source != null) {
                source.close();
            }
            if (destination != null) {
                destination.close();
            }
        }
    }

    public static void main(String args[]) {
       try {
        File sourceFile = new File("D:/new folder/abc.jpg");
        File destFile = new File("d:/new folder1/abc.jpg");
        copyFile(sourceFile,destFile);
        } catch (IOException ex) {
           ex.printStackTrace();
         }
    }
}

Answer 1

这是根据您的规范调整图像大小的代码。在 copyFile 方法中，

int width=100,height=75; /* set the width and height here */
BufferedImage inputImage=ImageIO.read(sourceFile);
BufferedImage outputImage=new BufferedImage(width, height,
    BufferedImage.TYPE_INT_RGB);
Graphics2D g=outputImage.createGraphics();
g.setRenderingHint(RenderingHints.KEY_INTERPOLATION,
    RenderingHints.VALUE_INTERPOLATION_BICUBIC);
g.clearRect(0, 0, width, height);
g.drawImage(inputImage, 0, 0, width, height, null);
g.dispose();
ImageIO.write(outputImage,"jpg",destFile);
/* first parameter is the object of the BufferedImage,
   second parameter is the type of image that you are going to write,
       you can use jpg, bmp, png etc
   third parameter is the destination file object. */