java 图片操作工具类

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package com.colin.tool.img;

import javax.imageio.ImageIO;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.*;

/**
 * @author colin.cheng
 * @date 2022-01-14 19:39
 * @since 1.0.0
 */
public class ImageBuilder {

    private BufferedImage bufferedImage;
    private Graphics graphics;

    private Font defaultFont = new Font(null, Font.BOLD, 28);
    private Color defaultColor = new Color(120, 120, 120);

    public ImageBuilder(int width, int height) {
        this(width, height, BufferedImage.TYPE_INT_BGR);
    }

    public ImageBuilder(File img) throws FileNotFoundException, IOException {
        try (final FileInputStream inputStream = new FileInputStream(img)) {
            init(ImageIO.read(inputStream));
        }
    }

    public ImageBuilder(BufferedImage bufferedImage) {
        init(bufferedImage);
    }

    public ImageBuilder(int width, int height, int imageType) {
        init(new BufferedImage(width, height, imageType));
    }

    private void init(BufferedImage bufferedImage) {
        this.bufferedImage = bufferedImage;
        graphics = bufferedImage.getGraphics();
        graphics.setColor(this.defaultColor);
        graphics.setFont(this.defaultFont);
    }

    public void drawText(String content, int x, int y) {
        graphics.drawString(content, x, y);
    }

    public void fillRect(int x, int y, int width, int height) {
        graphics.fillRect(x, y, width, height);
    }

    public void drawImg(BufferedImage img, int x, int y, int w, int h) {
        graphics.drawImage(img, x, y, w, h, null);
    }

    public ImageBuilder cut(int x, int y, int w, int h) {
        final BufferedImage subImage = bufferedImage.getSubimage(x, y, w, h);
        return new ImageBuilder(subImage);
    }

    public BufferedImage toImage() {
        return this.bufferedImage;
    }

    public boolean writeToFile(File file, String imgType) throws IOException {
        return ImageIO.write(this.bufferedImage, imgType, file);
    }


    // setter

    public void setFont(Font font) {
        graphics.setFont(font);
    }

    public void setColor(Color color) {
        graphics.setColor(color);
    }

    public int getWidth() {
        return bufferedImage.getWidth();
    }

    public int getHeight() {
        return bufferedImage.getHeight();
    }

    // static
}

• 视频截取关键帧

package com.colin.tool.img;

import java.awt.*;
import java.awt.image.BufferedImage;

/**
 * @author colin.cheng
 * @date 2022-01-17
 * @since 1.0.0
 */
public class ImageUtil {

    public static ImageBuilder getComicStrip(BufferedImage[] imgArray, int outHeight) {
        int showW = outHeight, showH = outHeight;
        final ImageBuilder imageBuilder = new ImageBuilder(showW * imgArray.length, showH, Color.BLACK);
        for (int i = 0; i < imgArray.length; i++) {
            BufferedImage image = imgArray[i];
            final int height = image.getHeight();
            final int width = image.getWidth();
            if (height == width) {
                imageBuilder.drawImg(image, i * showW, 0, showW, showH);
            } else {
                if(height > width) {
                    double n = (double) height / showH;
                    double w = width / n;
                    imageBuilder.drawImg(image, (int)(showW * i + (showH - w) / 2), 0, (int)w, showH);
                } else {
                    double n = (double) width / showW;
                    double h = height / n;
                    imageBuilder.drawImg(image, showW * i, (int)((showW - h) / 2), showW, (int)h);
                }
            }
        }
        return imageBuilder;
    }

    public static ImageBuilder addComicStripIndex(BufferedImage comicStrip, float transparency, int strokeWidth) {
        final int width = comicStrip.getWidth(), height = comicStrip.getHeight(), offset = height;
        int length = width / height;
        final ImageBuilder imageBuilder = new ImageBuilder(width + offset, height);
        BufferedImage banner = ImageBuilder.cut(comicStrip, 0, 0, height, height);
        imageBuilder.drawImg(banner, 0, 0, height, height);
        imageBuilder.drawImg(comicStrip, offset, 0, width, height);
        for (int i = 0; i < length; i++) {
            double w = height - strokeWidth, base = width / w, h = height / base;
            final int x = height * i + offset + strokeWidth / 2, y = (int)(height - h);
            imageBuilder.drawTranslucentImage(comicStrip, x, y, (int)w, (int)h, transparency);
            // 画框
            if(strokeWidth > 0) {
                imageBuilder.setColor(Color.BLACK);
                imageBuilder.drawRect(x + (i * (int)h), y, (int)h, (int)h, strokeWidth);
            }
            // 当前所在的关键帧变清晰
            if(transparency < 1) {
                BufferedImage frame = ImageBuilder.cut(comicStrip, height * i, 0, height, height);
                imageBuilder.drawImg(frame, x + (i * (int)h), y, (int)h, (int)h);
            }
        }
        return imageBuilder;
    }
}

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