欢迎您访问程序员文章站本站旨在为大家提供分享程序员计算机编程知识!
您现在的位置是: 首页

使用Java的ImageIO的图片处理实现  

程序员文章站 2022-06-04 15:24:35
...
import java.awt.Graphics2D;
import java.awt.Image;
import java.awt.RenderingHints;
import java.awt.image.BufferedImage;
import java.awt.image.ColorModel;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

import javax.imageio.IIOImage;
import javax.imageio.ImageIO;
import javax.imageio.ImageWriteParam;
import javax.imageio.ImageWriter;
import javax.imageio.stream.ImageOutputStream;

import com.ysccc.api.parent.constant.ProjectException;
import com.ysccc.api.parent.vo.Messages;

public class ImageCompress {

	private static BufferedImage loadImage(InputStream in) throws IOException {
		return ImageIO.read(in);
	}

	private static BufferedImage loadImage(String filePath) throws IOException {
		FileInputStream is = null;
		BufferedImage image = null;
		try {
			File file = new File(filePath);
			if (file.exists() && file.isFile() && file.canRead()) {
				is = new FileInputStream(file);
				image = loadImage(is);
			} else {
				throw new ProjectException(Messages.IMAGE_FILE_READ_FAIL);
			}
		} catch (Exception e) {
			throw e;
		} finally {
			if (is != null) {
				is.close();
			}
		}
		return image;
	}

	private static BufferedImage resizeImage(BufferedImage oldImage, int width, int height) throws IOException {
		int oldWidth = oldImage.getWidth();
		int oldHeight = oldImage.getHeight();
		ColorModel colorModel = oldImage.getColorModel();
		BufferedImage newImage = new BufferedImage(colorModel, colorModel.createCompatibleWritableRaster(width, height),
				colorModel.isAlphaPremultiplied(), null);
		// 说是能扫描的更清楚的写法,咱没感觉出来
		Image img = oldImage.getScaledInstance(oldWidth, oldHeight, Image.SCALE_SMOOTH);
		Graphics2D graphics = newImage.createGraphics();
		// 说是能抗锯齿,能平滑,能……,实际完全没感觉,是不是写的有问题呢
		graphics.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
		graphics.setRenderingHint(RenderingHints.KEY_TEXT_ANTIALIASING, RenderingHints.VALUE_TEXT_ANTIALIAS_ON);
		graphics.drawImage(img, 0, 0, width, height, null);
		return newImage;
	}

	private static ImageWriteParam configCompressParam(ImageWriter writer, float quality) {
		ImageWriteParam param = writer.getDefaultWriteParam();
		param.setCompressionMode(ImageWriteParam.MODE_EXPLICIT);
		param.setCompressionQuality(quality);
		return param;
	}

	private static void writeImage(ImageWriter writer, String filePath, BufferedImage image, float quality) throws IOException {
		OutputStream os = null;
		ImageOutputStream ios = null;
		try {
			os = new FileOutputStream(new File(filePath));
			ios = ImageIO.createImageOutputStream(os);
			writer.setOutput(ios);
			writer.write(null, new IIOImage(image, null, null), configCompressParam(writer, quality));
		} catch (Exception e) {
			throw e;
		} finally {
			if (os != null) {
				os.close();
			}
			if (ios != null) {
				ios.close();
			}
			if (writer != null) {
				writer.dispose();
			}
		}
	}

	private static ImageWriter getWriter(String imageSuffix) {
		return ImageIO.getImageWritersByFormatName(imageSuffix).next();
	}

	public static void main(String[] args) throws IOException {
		BufferedImage oImage = loadImage("C:\\Users\\Administrator\\Desktop\\bigImage\\_G7A2008.JPG");
		BufferedImage nImage = resizeImage(oImage, (int) (oImage.getWidth() / 2), (int) (oImage.getHeight() / 2));
		ImageWriter writer = getWriter("jpg");
		writeImage(writer, "C:\\Users\\Administrator\\Desktop\\bigImage\\compress1.jpg", nImage, 0.5f);
	}
}


写了这么多,如果按比例缩小图片的话,会发现一点都不清楚,按质量倒是没什么问题。
于是就放弃这种写法了,改用了Google的Thumbnails,发现简直差距太大了,唉……原生的代码果然不行啊
Thumbnails.of(new File("C:\\Users\\Administrator\\Desktop\\bigImage\\7.jpg")).scale(1f).outputFormat("jpg")
	.outputQuality(0.5)
	.toFile("C:\\Users\\Administrator\\Desktop\\bigImage\\compress2.jpg");