图片转ASCII字符画

实现原理

将图片分解为像素点然后计算出每个点的灰度值，根据不同灰度使用不同的字符进行填充。
以下代码实现了将图片缩放至指定宽高并转换为ASCII字符画的功能。

package com.wunian.ascii;

import javax.imageio.ImageIO;
import java.awt.*;
import java.awt.geom.AffineTransform;
import java.awt.image.AffineTransformOp;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import java.util.UUID;

/**
 * @author wunian
 * @desc  实现图片转AscII字符画
 * @createTime 2020/7/15
 */
public class AsciiPicDemo {

    public static void main(final String[] args) throws Exception {
        String src = "C:\\Users\\My\\Desktop\\1.gif";
        String dest = src.substring(0,src.lastIndexOf("\\")+1)+"_"+ UUID.randomUUID()+"_"+src.substring(src.lastIndexOf("\\")+1);
        String path = zoomImage(src,dest,80,50);
        createAsciiPic(path);
    }

    /**
     * 生成ASCII字符画
     * @param path 图片路径
     */
    public static void createAsciiPic(String path) {
        final String base = "▬@*&$^";// 字符串由复杂到简单
        try {
            BufferedImage image = ImageIO.read(new File(path));
           //可以通过改变x和y的步长来控制字符画的字符稀疏程度
            for (int y = 0; y < image.getHeight(); y += 1) {
                for (int x = 0; x < image.getWidth(); x += 1) {
                    final int pixel = image.getRGB(x, y);
                    final int r = (pixel & 0xff0000) >> 16, g = (pixel & 0xff00) >> 8, b = pixel & 0xff;
                    final float gray = 0.299f * r + 0.578f * g + 0.114f * b;
                    final int index = Math.round(gray * (base.length() + 1) / 255);
                    System.out.print(index >= base.length() ? " " : String.valueOf(base.charAt(index)));
                }
                System.out.println();
            }
        } catch (final IOException e) {
            e.printStackTrace();
        }
        new File(path).delete();//删除临时文件
    }

    /**
     * 图片缩放，生成指定宽高的目标图片
     * @param src 源文件目录
     * @param dest 缩放后保存目录
     * @param w 缩放的目标宽度
     * @param h 缩放的目标高度
     * @return
     * @throws Exception
     */
    public static String zoomImage(String src,String dest,int w,int h) throws Exception {

        double wr=0,hr=0;
        File srcFile = new File(src);
        File destFile = new File(dest);

        BufferedImage bufImg = ImageIO.read(srcFile); //读取图片
        System.out.println("width:"+bufImg.getWidth());
        System.out.println("height:"+bufImg.getHeight());
        Image Itemp = bufImg.getScaledInstance(w, h, bufImg.SCALE_SMOOTH);//设置缩放目标图片模板

        wr=w*1.0/bufImg.getWidth();     //获取缩放比例
        hr=h*1.0 / bufImg.getHeight();

        AffineTransformOp ato = new AffineTransformOp(AffineTransform.getScaleInstance(wr, hr), null);
        Itemp = ato.filter(bufImg, null);
        try {
            ImageIO.write((BufferedImage) Itemp,dest.substring(dest.lastIndexOf(".")+1), destFile); //写入缩减后的图片
        } catch (Exception ex) {
            ex.printStackTrace();
        }
        System.out.println("getAbsoultePath:"+destFile.getAbsolutePath());
        return destFile.getAbsolutePath();
    }
}

效果图如下：