将图像裁剪成圆形

Posted 2023-02-25

【中文标题】将图像裁剪成圆形

【英文标题】：Cropping image into circle

【发布时间】：2014-06-18 21:06:26

【问题描述】：

我想从我的原始图像中裁剪出一个圆形图像。我正在使用 Picasso 库进行图像显示。试过http://yasiradnan.com/circle-transformation-with-android-image-downloading-and-caching-library-picasso/，但它只是将整个图像转换成一个圆形，所以图像变形了。我不想转换图像，我只想用圆形裁剪图像。

【问题讨论】：

我不知道如何使用毕加索，但这可能会对你有所帮助：***.com/questions/12944275/…

【参考方案1】：

要完成你想要做的事情，你可以继承ImageView 并使其实现Picasso 的Target 接口。加载位图时，只需使用将位图中心裁剪为正方形，然后将图像着色为圆形的方法。例如：

public class ImageViewTarget extends ImageView implements Target 

    //constructors

@Override
public void onBitmapFailed(Drawable drawable) 
         //TODO


@Override
public void onBitmapLoaded(Bitmap bitmap, LoadedFrom loadFrom) 
       bitmap = cropCircle(bitmap.isMutable() ? bitmap : bitmap.copy(Config.ARGB_8888, true));
           setImageBitmap(bitmap);


@Override
public void onPrepareLoad(Drawable arg0) 
     //TODO



public Bitmap cropCricle(Bitmap bm)

    int width = bm.getWidth();
    int height = bm.getHeight();

    Bitmap cropped_bitmap;

    /* Crop the bitmap so it'll display well as a circle. */
    if (width > height) 
        cropped_bitmap = Bitmap.createBitmap(bm,
                (width / 2) - (height / 2), 0, height, height);
     else 
        cropped_bitmap = Bitmap.createBitmap(bm, 0, (height / 2)
                - (width / 2), width, width);
    

    BitmapShader shader = new BitmapShader(cropped_bitmap, TileMode.CLAMP, TileMode.CLAMP);

    Paint paint = new Paint();
    paint.setAntiAlias(true);
    paint.setShader(shader);

    height = cropped_bitmap.getHeight();
    width = cropped_bitmap.getWidth();

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

    Canvas canvas = new Canvas(mCanvasBitmap);
    canvas.drawCircle(width/2, height/2, width/2, paint);

    return mCanvasBitmap;

处理cropCircle(Bitmap bitmap); 方法的原因可能更好，但上述方法有时可以优化/构建。

【参考方案2】：

您可以使用以下代码获取圆角位图...这可能对您有帮助 ....

   private Bitmap getRoundedCroppedImage(Bitmap bmp) 
        int widthLight = bmp.getWidth();
        int heightLight = bmp.getHeight();

        Bitmap output = Bitmap.createBitmap(widthLight, heightLight,Config.ARGB_8888);

        Canvas canvas = new Canvas(output);
        Paint paint = new Paint();
        paint.setFlags(Paint.ANTI_ALIAS_FLAG);

        RectF rectF = new RectF(new Rect(0, 0, widthLight, heightLight));

        canvas.drawRoundRect(rectF, widthLight / 2 ,heightLight / 2,paint);

        Paint paintImage = new Paint();
        paintImage.setXfermode(new PorterDuffXfermode(Mode.SRC_ATOP));
        canvas.drawBitmap(bmp, 0, 0, paintImage);

        return output;
    

谢谢...

【参考方案3】：

我根据that answer做了一些决定 您可以制作没有库的自定义 ImageView

import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.Bitmap.Config;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.PorterDuff.Mode;
import android.graphics.PorterDuffXfermode;
import android.graphics.Rect;
import android.graphics.drawable.BitmapDrawable;
import android.graphics.drawable.Drawable;
import android.util.AttributeSet;
import android.widget.ImageView;

public class CircleImageView extends ImageView 

    public CircleImageView(Context ctx, AttributeSet attrs) 
        super(ctx, attrs);
    

    @Override
    public void setImageDrawable(Drawable aDrawable) 
        Bitmap bitmap=getCircleCroppedBitmap(((BitmapDrawable) aDrawable).getBitmap());
        super.setImageDrawable(new BitmapDrawable(getResources(),bitmap));
    

    private static Bitmap getCircleCroppedBitmap(Bitmap bitmap) 
        Bitmap output = Bitmap.createBitmap(bitmap.getWidth(),
                bitmap.getHeight(), Config.ARGB_8888);
        Canvas canvas = new Canvas(output);

        final int color = 0xff424242;
        final Paint paint = new Paint();
        final Rect rect = new Rect(0, 0, bitmap.getWidth(), bitmap.getHeight());

        paint.setAntiAlias(true);
        canvas.drawARGB(0, 0, 0, 0);
        paint.setColor(color);
        // canvas.drawRoundRect(rectF, roundPx, roundPx, paint);
        canvas.drawCircle(bitmap.getWidth() / 2, bitmap.getHeight() / 2,
                bitmap.getWidth() / 2, paint);
        paint.setXfermode(new PorterDuffXfermode(Mode.SRC_IN));
        canvas.drawBitmap(bitmap, rect, rect, paint);
        //Bitmap _bmp = Bitmap.createScaledBitmap(output, 60, 60, false);
        //return _bmp;
        return output;