拼接两张图片分为两种情况,两者宽度相同和两者宽度不同

两者宽度相同

//创建一个两张图片高度相加的bitmap对象
Bitmap retBmp = Bitmap.createBitmap(width, bitmapFirst.getHeight() + bitmapSecond.getHeight(), Bitmap.Config.ARGB_8888);
Canvas canvas = new Canvas(retBmp);
//依次绘制两张图片至对应bitmap对象
canvas.drawBitmap(bitmapFirst, 0, 0, null);
canvas.drawBitmap(bitmapSecond, 0, bitmapFirst.getHeight(), null);

两者宽度不相同

//获取两张图片的宽度比
int h2 = bitmapSecond.getHeight() * width / bitmapSecond.getWidth();
Bitmap retBmp = Bitmap.createBitmap(width, bitmapFirst.getHeight() + h2, Bitmap.Config.ARGB_8888);
Canvas canvas = new Canvas(retBmp);
//以第一张图片的宽度为基准对第二张图片的宽度和高度进行缩放
Bitmap newSizeBmp2 = resizeBitmap(bitmapSecond, width, h2);
//依次绘制两张图片
canvas.drawBitmap(bitmapFirst, 0, 0, null);
canvas.drawBitmap(newSizeBmp2, 0, bitmapFirst.getHeight(), null);

缩放操作

    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;
    }

附上整个代码:

public class CombineImage {

    //将两张图片合成一张
    public static Bitmap doCombineTask(Bitmap bitmapFirst, Bitmap bitmapSecond){
        Bitmap retBmp;
        int width = bitmapFirst.getWidth();
        if (bitmapSecond.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 = bitmapSecond.getHeight() * width / bitmapSecond.getWidth();
            retBmp = Bitmap.createBitmap(width, bitmapFirst.getHeight() + h2, Bitmap.Config.ARGB_8888);
            Canvas canvas = new Canvas(retBmp);
            Bitmap newSizeBmp2 = resizeBitmap(bitmapSecond, width, h2);
            canvas.drawBitmap(bitmapFirst, 0, 0, null);
            canvas.drawBitmap(newSizeBmp2, 0, bitmapFirst.getHeight(), null);
        } else {
            //两张图片宽度相等，则直接拼接。
            retBmp = Bitmap.createBitmap(width, bitmapFirst.getHeight() + bitmapSecond.getHeight(), Bitmap.Config.ARGB_8888);
            Canvas canvas = new Canvas(retBmp);
            canvas.drawBitmap(bitmapFirst, 0, 0, null);
            canvas.drawBitmap(bitmapSecond, 0, bitmapFirst.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;
    }
}