掩蔽（裁剪）帧中的图像

Posted 2023-02-14

【中文标题】掩蔽（裁剪）帧中的图像

【英文标题】：Masking(crop) image in frame

【发布时间】：2012-09-18 20:02:52

【问题描述】：

有一个丰富的 UI 应用程序，我想在其中显示像这样复杂形状的图像

现在我想要的是按照蒙版图像裁剪我的图像，实际上 图像是动态的，可以从相机或图库（方形或矩形形状）导入，我希望该图像适合在我上面的布局框架中

所以只是想知道我是如何实现这一目标的？任何想法/提示欢迎

背景框面具

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【参考方案1】：

在更改蒙版图像并使用Xfermode和Bitmap时终于得到了解决方案

面具

 ImageView mImageView= (ImageView)findViewById(R.id.imageview_id);
 Bitmap original = BitmapFactory.decodeResource(getResources(),R.drawable.content_image);
 Bitmap mask = BitmapFactory.decodeResource(getResources(),R.drawable.mask);
 Bitmap result = Bitmap.createBitmap(mask.getWidth(), mask.getHeight(), Config.ARGB_8888);
 Canvas mCanvas = new Canvas(result);
 Paint paint = new Paint(Paint.ANTI_ALIAS_FLAG);
 paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.DST_IN));
 mCanvas.drawBitmap(original, 0, 0, null);
 mCanvas.drawBitmap(mask, 0, 0, paint);
 paint.setXfermode(null);
 mImageView.setImageBitmap(result);
 mImageView.setScaleType(ScaleType.CENTER);
 mImageView.setBackgroundResource(R.drawable.background_frame);

查看输出

来源可以找到here

【讨论】：

你好@hotveryspicy，感谢示例代码，它帮助很大。我面临一些问题，一些小提示对我来说会有很长的路要走。我想以绘制的一些多边形形状切割位图。我的位图切割成多边形，但裁剪位图的内容取自左上角，即原始位图的 0,0。我想要绘制多边形的下面的内容。

@Nidhi 你可以创建相同的缩放位图。

@hotveryspicy 谢谢你的回复。实际上我想做这里给出的同样的事情。 ***.com/questions/15969028/…。我的问题是裁剪位图是从左上角裁剪，即 0,0。不形成我指定的路径。我也放了代码。请指导我哪里出错了。

感谢@hotveryspicy，对于任何需要它的人，我做了一个简单的叉子，可以帮助将图像缩放到面具的大小：github.com/worker8/MaskImage/tree/master

要缩放蒙版以适应图像，我使用这一行：Bitmap resized = Bitmap.createScaledBitmap(mask, original.getWidth(), original.getHeight(), true);并使用 mCanvas.drawBitmap(original, 0, 0, null); mCanvas.drawBitmap(resized, 0, 0, paint);

【参考方案2】：

使用 Picasso 库和自定义转换更容易：

MaskTransformation.java：

 * ORIGINAL:
 * Copyright (C) 2015 Wasabeef
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package me.monori.example.utilities;

import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.PorterDuff;
import android.graphics.PorterDuffXfermode;
import android.graphics.drawable.Drawable;
import android.support.v4.content.ContextCompat;

import com.squareup.picasso.Transformation;

public class MaskTransformation implements Transformation 

    private static Paint mMaskingPaint = new Paint();
    private Context mContext;
    private int mMaskId;

    static 
        mMaskingPaint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SRC_IN));
    

    /**
     * @param maskId If you change the mask file, please also rename the mask file, or Glide will get
     * the cache with the old mask. Because getId() return the same values if using the
     * same make file name. If you have a good idea please tell us, thanks.
     */
    public MaskTransformation(Context context, int maskId) 
        mContext = context.getApplicationContext();
        mMaskId = maskId;
    

    @Override public Bitmap transform(Bitmap source) 
        int width = source.getWidth();
        int height = source.getHeight();

        Bitmap result = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);

        Drawable mask = getMaskDrawable(mContext, mMaskId);

        Canvas canvas = new Canvas(result);
        mask.setBounds(0, 0, width, height);
        mask.draw(canvas);
        canvas.drawBitmap(source, 0, 0, mMaskingPaint);

        source.recycle();

        return result;
    

    @Override public String key() 
        return "MaskTransformation(maskId=" + mContext.getResources().getResourceEntryName(mMaskId)
                + ")";
    

    public Drawable getMaskDrawable(Context context, int maskId) 
        Drawable drawable = ContextCompat.getDrawable(context, maskId);

        if (drawable == null) 
            throw new IllegalArgumentException("maskId is invalid");
        

        return drawable;
    

然后简单地在一行中定义它：

Picasso.with(context)
                    .load(imageUrl)
                    .transform(new MaskTransformation(context, _maskDrawableId))
                    .placeholder(R.drawable.drawableId)
                    .into(imageView);

【参考方案3】：

     final ImageView mImageView = (ImageView) findViewById(R.id.image);
     mImageView.setBackgroundResource(R.drawable.user_outer_circle_icon);


     mImageView.setOnClickListener(new OnClickListener() 

        @Override
        public void onClick(View v) 


            if(b)
                 mImageView.setBackgroundResource(R.drawable.profil_circle);

                 Bitmap original = BitmapFactory.decodeResource(getResources(),R.drawable.doge);

                 Bitmap mask = BitmapFactory.decodeResource(getResources(),R.drawable.mask_white);

                 Bitmap mask1 = BitmapFactory.decodeResource(getResources(),R.drawable.pencil_bg);

                 original = Bitmap.createScaledBitmap(original, mask.getWidth(),mask.getHeight(), true);

                 Bitmap result = Bitmap.createBitmap(mask.getWidth(), mask.getHeight(),Config.ARGB_8888);
                 Canvas mCanvas = new Canvas(result);
                 Paint paint = new Paint(Paint.ANTI_ALIAS_FLAG);
                 paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.DST_IN));
                 mCanvas.drawBitmap(original, 0, 0, null);
                 mCanvas.drawBitmap(mask, 0, 0, paint);
                 mCanvas.drawBitmap(mask1, 0, 0, null);
                 Bitmap mask2 = BitmapFactory.decodeResource(getResources(), R.drawable.ic_pencil);
                 mCanvas.drawBitmap(mask2, 0, 0, null);
                 mImageView.setImageBitmap(result);
                 mImageView.setScaleType(ScaleType.FIT_XY);

                 b=false;
             else
                 ImageView mImageView = (ImageView) findViewById(R.id.image);
                 Bitmap original = BitmapFactory.decodeResource(getResources(),
                 R.drawable.doge);

                 Bitmap mask = BitmapFactory.decodeResource(getResources(),
                 R.drawable.mask_white);

                 original = Bitmap.createScaledBitmap(original, mask.getWidth(),
                 mask.getHeight(), true);

                 Bitmap result = Bitmap.createBitmap(mask.getWidth(), mask.getHeight(),
                 Config.ARGB_8888);
                 Canvas mCanvas = new Canvas(result);
                 Paint paint = new Paint(Paint.ANTI_ALIAS_FLAG);
                 paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.DST_IN));
                 mCanvas.drawBitmap(original, 0, 0, null);
                 mCanvas.drawBitmap(mask, 0, 0, paint);
                 paint.setXfermode(null);
                 mImageView.setImageBitmap(result);
                 mImageView.setScaleType(ScaleType.FIT_XY);
                // mImageView.setBackgroundResource(R.drawable.user_outer_circle_icon);
                 b= true;


             


        
    );

【参考方案4】：

这个例子用掩码“animation_mask”屏蔽了他的子元素（Imageview）

<com.christophesmet.android.views.maskableframelayout.MaskableFrameLayout
android:id="@+id/frm_mask_animated"
android:layout_
app:porterduffxfermode="DST_IN"
app:mask="@drawable/animation_mask"
android:layout_>

<ImageView android:layout_
           android:layout_
           android:scaleType="centerCrop"
           android:src="@drawable/unicorn"/>

check this git link