Android拼接合并图片生成长图

r囧r小猫 2023-10-17 21:58 51阅读 0赞

**Android拼接合并图片生成长图**

代码实现合并两张图片，以第一张图片的宽度为标准，如果被合并的第二张图片宽度和第一张不同，那么就以第一张图片的宽度为准线，对第二张图片进行缩放。

假设根目录的Pictures下已经有两张图片zhang.jpg和phil.jpg，最终把这两张图片合并成zhangphil.jpg的长图：

package zhangphil.test;
    
    import android.graphics.Bitmap;
    import android.graphics.BitmapFactory;
    import android.graphics.Canvas;
    import android.graphics.Matrix;
    import android.os.Bundle;
    import android.os.Environment;
    import android.support.annotation.Nullable;
    import android.support.v7.app.AppCompatActivity;
    import android.view.View;
    
    import java.io.BufferedOutputStream;
    import java.io.File;
    import java.io.FileInputStream;
    import java.io.FileOutputStream;
    import java.io.IOException;
    import java.io.OutputStream;
    
    public class JavaActivity extends AppCompatActivity {
    
        @Override
        protected void onCreate(@Nullable Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.drawable_activity);
    
            findViewById(R.id.button).setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    merge();
                }
            });
        }
    
        private void merge() {
            new Thread(new Runnable() {
                @Override
                public void run() {
                    File zhang = new File(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES), "zhang.jpg");
                    File phil = new File(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES), "phil.jpg");
    
                    try {
                        Bitmap bitmap1 = BitmapFactory.decodeStream(new FileInputStream(zhang));
                        Bitmap bitmap2 = BitmapFactory.decodeStream(new FileInputStream(phil));
    
                        Bitmap newBmp = newBitmap(bitmap1, bitmap2);
    
                        File zhangphil = new File(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES), "zhangphil.jpg");
                        if (!zhangphil.exists())
                            zhangphil.createNewFile();
                        save(newBmp, zhangphil, Bitmap.CompressFormat.JPEG, true);
                    } catch (Exception e) {
                        e.printStackTrace();
                    }
                }
            }).start();
        }
    
        public static Bitmap newBitmap(Bitmap bmp1, Bitmap bmp2) {
            Bitmap retBmp;
            int width = bmp1.getWidth();
            if (bmp2.getWidth() != width) {
                //以第一张图片的宽度为标准，对第二张图片进行缩放。
    
                int h2 = bmp2.getHeight() * width / bmp2.getWidth();
                retBmp = Bitmap.createBitmap(width, bmp1.getHeight() + h2, Bitmap.Config.ARGB_8888);
                Canvas canvas = new Canvas(retBmp);
                Bitmap newSizeBmp2 = resizeBitmap(bmp2, width, h2);
                canvas.drawBitmap(bmp1, 0, 0, null);
                canvas.drawBitmap(newSizeBmp2, 0, bmp1.getHeight(), null);
            } else {
                //两张图片宽度相等，则直接拼接。
                
                retBmp = Bitmap.createBitmap(width, bmp1.getHeight() + bmp2.getHeight(), Bitmap.Config.ARGB_8888);
                Canvas canvas = new Canvas(retBmp);
                canvas.drawBitmap(bmp1, 0, 0, null);
                canvas.drawBitmap(bmp2, 0, bmp1.getHeight(), null);
            }
    
            return retBmp;
        }
    
        public static Bitmap resizeBitmap(Bitmap bitmap, int newWidth, int newHeight) {
            float scaleWidth = ((float) newWidth) / bitmap.getWidth();
            float scaleHeight = ((float) newHeight) / bitmap.getHeight();
            Matrix matrix = new Matrix();
            matrix.postScale(scaleWidth, scaleHeight);
            Bitmap bmpScale = Bitmap.createBitmap(bitmap, 0, 0, bitmap.getWidth(), bitmap.getHeight(), matrix, true);
            return bmpScale;
        }
    
        /**
         * 保存图片到文件File。
         *
         * @param src     源图片
         * @param file    要保存到的文件
         * @param format  格式
         * @param recycle 是否回收
         * @return true 成功 false 失败
         */
        public static boolean save(Bitmap src, File file, Bitmap.CompressFormat format, boolean recycle) {
            if (isEmptyBitmap(src))
                return false;
    
            OutputStream os;
            boolean ret = false;
            try {
                os = new BufferedOutputStream(new FileOutputStream(file));
                ret = src.compress(format, 100, os);
                if (recycle && !src.isRecycled())
                    src.recycle();
            } catch (IOException e) {
                e.printStackTrace();
            }
    
            return ret;
        }
    
        /**
         * Bitmap对象是否为空。
         */
        public static boolean isEmptyBitmap(Bitmap src) {
            return src == null || src.getWidth() == 0 || src.getHeight() == 0;
        }
    }

合并后生成的长图：

![70][]

添加权限：

<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />

[70]: https://img-blog.csdn.net/20180620105428917?watermark/2/text/aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3poYW5ncGhpbA==/font/5a6L5L2T/fontsize/400/fill/I0JBQkFCMA==/dissolve/70