话不多说，直接上代码

import java.awt.image.BufferedImage;

import java.awt.image.Raster;

import java.io.File;

import java.io.IOException;

import javax.imageio.ImageIO;

public class IOUtil {

public static void pgm2png(String src, String dest) throws IOException {

BufferedImage image = ImageIO.read(new File(src));

Raster source = image.getRaster();

int width = image.getWidth();

int height = image.getHeight();

// 创建BufferedImage对象

// BufferedImage image2 = new BufferedImage(width,

// height,BufferedImage.TYPE_BYTE_BINARY);//黑色

BufferedImage image2 = new BufferedImage(width, height, BufferedImage.TYPE_BYTE_GRAY);// 灰色

// BufferedImage image2 = new BufferedImage(width, height,

// BufferedImage.TYPE_BYTE_INDEXED);//黄色

image2.setData(source);

// 保存文件

ImageIO.write(image2, "png", new File(dest));

}

}

上述代码中，有几个参数需要在格式转换的时候调整。\

new BufferedImage(width, height, BufferedImage.TYPE_BYTE_GRAY)的第三个参数，图片格式类型

ImageIO.write(image2, "png", new File(dest)); 的第二个参数，转换的目标图片格式