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：

添加权限：