[英]How to crop circular area from bitmap in Android
我有一個位圖,我想從這個位圖中裁剪一個圓形區域。 圓圈外的所有像素都應該是透明的。 我怎樣才能做到這一點?
經過長時間的頭腦風暴,我找到了解決方案
public Bitmap getCroppedBitmap(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;
}
public static Bitmap getCircularBitmap(Bitmap bitmap) {
Bitmap output;
if (bitmap.getWidth() > bitmap.getHeight()) {
output = Bitmap.createBitmap(bitmap.getHeight(), bitmap.getHeight(), Config.ARGB_8888);
} else {
output = Bitmap.createBitmap(bitmap.getWidth(), bitmap.getWidth(), 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());
float r = 0;
if (bitmap.getWidth() > bitmap.getHeight()) {
r = bitmap.getHeight() / 2;
} else {
r = bitmap.getWidth() / 2;
}
paint.setAntiAlias(true);
canvas.drawARGB(0, 0, 0, 0);
paint.setColor(color);
canvas.drawCircle(r, r, r, paint);
paint.setXfermode(new PorterDuffXfermode(Mode.SRC_IN));
canvas.drawBitmap(bitmap, rect, rect, paint);
return output;
}
您可以使用RoundedBitmapDrawable使 imageview 成為圓形
這是實現roundedImageview的代碼:
ImageView profilePic=(ImageView)findViewById(R.id.user_image);
//get bitmap of the image
Bitmap imageBitmap=BitmapFactory.decodeResource(getResources(), R.drawable.large_icon);
RoundedBitmapDrawable roundedBitmapDrawable=RoundedBitmapDrawableFactory.create(getResources(), imageBitmap);
//setting radius
roundedBitmapDrawable.setCornerRadius(50.0f);
roundedBitmapDrawable.setAntiAlias(true);
profilePic.setImageDrawable(roundedBitmapDrawable);
@Gene 對上面的答案發表了評論,建議使用clipPath
作為將圖像裁剪為圓形的選項。
以下是一個干凈的實現:
public static Bitmap GetBitmapClippedCircle(Bitmap bitmap) {
final int width = bitmap.getWidth();
final int height = bitmap.getHeight();
final Bitmap outputBitmap = Bitmap.createBitmap(width, height, Config.ARGB_8888);
final Path path = new Path();
path.addCircle(
(float)(width / 2)
, (float)(height / 2)
, (float) Math.min(width, (height / 2))
, Path.Direction.CCW);
final Canvas canvas = new Canvas(outputBitmap);
canvas.clipPath(path);
canvas.drawBitmap(bitmap, 0, 0, null);
return outputBitmap;
}
這可以添加到實用程序類。
我認為此解決方案適用於任何類型的矩形,如果您希望圖像變小或變大,請更改像素大小:
public static Bitmap getCircleBitmap(Bitmap bm) {
int sice = Math.min((bm.getWidth()), (bm.getHeight()));
Bitmap bitmap = ThumbnailUtils.extractThumbnail(bm, sice, sice);
Bitmap output = Bitmap.createBitmap(bitmap.getWidth(), bitmap.getHeight(), Bitmap.Config.ARGB_8888);
Canvas canvas = new Canvas(output);
final int color = 0xffff0000;
final Paint paint = new Paint();
final Rect rect = new Rect(0, 0, bitmap.getWidth(), bitmap.getHeight());
final RectF rectF = new RectF(rect);
paint.setAntiAlias(true);
paint.setDither(true);
paint.setFilterBitmap(true);
canvas.drawARGB(0, 0, 0, 0);
paint.setColor(color);
canvas.drawOval(rectF, paint);
paint.setColor(Color.BLUE);
paint.setStyle(Paint.Style.STROKE);
paint.setStrokeWidth((float) 4);
paint.setXfermode(new PorterDuffXfermode(Mode.SRC_IN));
canvas.drawBitmap(bitmap, rect, rect, paint);
return output;
}
這也可以在 xml 中輕松完成,而無需裁剪實際位圖,您只需要創建一個圓形圖像蒙版並放置在您的實際圖像上。 這是我使用的一段代碼:
<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android" android:shape="oval" >
<gradient android:startColor="#00FFFFFF" android:endColor="#00FFFFFF"
android:angle="270"/>
<stroke android:width="10dp" android:color="#FFAAAAAA"/>
<RelativeLayout
android:id="@+id/icon_layout"
android:layout_width="@dimen/icon_mask"
android:layout_height="@dimen/icon_mask"
android:layout_alignParentLeft="true"
android:layout_alignParentTop="true" >
<ImageView
android:id="@+id/icon"
android:layout_width="@dimen/icon"
android:layout_height="@dimen/icon"
android:layout_centerInParent="true"
android:scaleType="fitXY" >
</ImageView>
<ImageView
android:id="@+id/icon_mask"
android:layout_width="@dimen/icon_mask"
android:layout_height="@dimen/icon_mask"
android:layout_centerInParent="true"
android:background="@drawable/circle"
android:scaleType="fitXY" >
</ImageView>
</RelativeLayout>
尺寸文件
<dimen name="icon">36dp</dimen>
<dimen name="icon_mask">55dp</dimen>
輸出圖像視圖:
希望,它可能對某人有用!!! :)
您可以使用此代碼,它將起作用
private Bitmap getCircleBitmap(Bitmap bitmap) {
final Bitmap output = Bitmap.createBitmap(bitmap.getWidth(),
bitmap.getHeight(), Bitmap.Config.ARGB_8888);
final Canvas canvas = new Canvas(output);
final int color = Color.RED;
final Paint paint = new Paint();
final Rect rect = new Rect(0, 0, bitmap.getWidth(), bitmap.getHeight());
final RectF rectF = new RectF(rect);
paint.setAntiAlias(true);
canvas.drawARGB(0, 0, 0, 0);
paint.setColor(color);
canvas.drawOval(rectF, paint);
paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SRC_IN));
canvas.drawBitmap(bitmap, rect, rect, paint);
bitmap.recycle();
return output;
}
您可以使用此代碼,它將起作用
public Bitmap getRoundedShape(Bitmap scaleBitmapImage) {
int targetWidth = 110;
int targetHeight = 110;
Bitmap targetBitmap = Bitmap.createBitmap(targetWidth,
targetHeight,Bitmap.Config.ARGB_8888);
Canvas canvas = new Canvas(targetBitmap);
Path path = new Path();
path.addCircle(((float) targetWidth - 1) / 2,
((float) targetHeight - 1) / 2,
(Math.min(((float) targetWidth),
((float) targetHeight)) / 2),
Path.Direction.CCW);
canvas.clipPath(path);
Bitmap sourceBitmap = scaleBitmapImage;
canvas.drawBitmap(sourceBitmap,
new Rect(0, 0, sourceBitmap.getWidth(),
sourceBitmap.getHeight()),
new Rect(0, 0, targetWidth, targetHeight), new Paint(Paint.FILTER_BITMAP_FLAG));
return targetBitmap;
}
如果你不再需要它,我建議添加bitmap.recycle()
,它會防止 OutOfMemory 錯誤。
這是使用擴展方法的 Kotlin 變體
/**
* Creates new circular bitmap based on original one.
*/
fun Bitmap.getCircularBitmap(config: Bitmap.Config = Bitmap.Config.ARGB_8888): Bitmap {
// circle configuration
val circlePaint = Paint().apply { isAntiAlias = true }
val circleRadius = Math.max(width, height) / 2f
// output bitmap
val outputBitmapPaint = Paint(circlePaint).apply { xfermode = PorterDuffXfermode(PorterDuff.Mode.SRC_IN) }
val outputBounds = Rect(0, 0, width, height)
val output = Bitmap.createBitmap(width, height, config)
return Canvas(output).run {
drawCircle(circleRadius, circleRadius, circleRadius, circlePaint)
drawBitmap(this@getCircularBitmap, outputBounds, outputBounds, outputBitmapPaint)
output
}
}
我相信最簡單的解決方案是為您的位圖創建一個 BitmapShader,將它傳遞給您的繪畫對象,然后簡單地調用像 canvas.drawCircle(cx, cy, radius, paint); 這樣的東西。
例如
Paint p = new Paint();
p.setShader(new BitmapShader(myBitmap, Shader.TileMode.CLAMP, Shader.TileMode.CLAMP));
canvas.drawCircle(getWidth() / 2, getHeight() / 2, getHeight() / 2, p);
https://github.com/hdodenhof/CircleImageView也是這樣做的,你可以在這里閱讀源代碼: https : //github.com/hdodenhof/CircleImageView/blob/master/circleimageview/src/main/java /de/hdodenhof/circleimageview/CircleImageView.java
對於想要矩形中心的人(我),在切割之前添加:
public static Bitmap cropBitmapToBlock(Bitmap bitmap) {
if (bitmap.getWidth() >= bitmap.getHeight()){
return Bitmap.createBitmap(
bitmap,
bitmap.getWidth()/2 - bitmap.getHeight()/2,
0,
bitmap.getHeight(),
bitmap.getHeight()
);
}else{
return Bitmap.createBitmap(
bitmap,
0,
bitmap.getHeight()/2 - bitmap.getWidth()/2,
bitmap.getWidth(),
bitmap.getWidth()
);
}
}
基於 [Jachumbelechao Unto Mantekilla] 的回答,這段代碼對尋找 Kotlin 解決方案的人來說就像一個魅力:
fun cropCircleFromBitmap(originalBitmap: Bitmap): Bitmap {
val size = Math.min(originalBitmap.width, originalBitmap.height)
val bitmap = ThumbnailUtils.extractThumbnail(originalBitmap, size, size)
var output = Bitmap.createBitmap(bitmap.width, bitmap.height, Bitmap.Config.ARGB_8888)
val canvas = Canvas(output)
val paint = Paint()
val rect = Rect(0, 0, bitmap.width, bitmap.height)
val rectF = RectF(rect)
paint.isAntiAlias = true
paint.isDither = true
paint.isFilterBitmap = true
canvas.drawARGB(0, 0, 0, 0)
paint.color = 0xffff0000.toInt()
canvas.drawOval(rectF, paint)
paint.color = Color.BLUE
paint.style = Paint.Style.STROKE
paint.strokeWidth = 4f
paint.xfermode = PorterDuffXfermode(PorterDuff.Mode.SRC_IN);
canvas.drawBitmap(bitmap, rect, rect, paint)
return output
}
現在,正確答案:
private Bitmap getCroppedBitmap(Bitmap bitmap, Integer cx, Integer cy, Integer radius) {
int diam = radius << 1;
Bitmap targetBitmap = Bitmap.createBitmap(diam, diam, Bitmap.Config.ARGB_8888);
Canvas canvas = new Canvas(targetBitmap);
final int color = 0xff424242;
final Paint paint = new Paint(Paint.ANTI_ALIAS_FLAG);
canvas.drawARGB(0, 0, 0, 0);
paint.setColor(color);
canvas.drawCircle(radius, radius, radius, paint);
paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SRC_IN));
canvas.drawBitmap(bitmap, -cx+radius, -cy+radius, paint);
return targetBitmap;
}
科廷函數
fun getRoundedCornerBitmap(bitmap: Bitmap, pixels: Int): Bitmap {
val output = Bitmap.createBitmap(bitmap.width, bitmap.height, Bitmap.Config.ARGB_8888)
val canvas = Canvas(output)
val color = -0xbdbdbe
val paint = Paint()
val rect = Rect(0, 0, bitmap.width, bitmap.height)
val rectF = RectF(rect)
val roundPx = pixels.toFloat()
paint.isAntiAlias = true
canvas.drawARGB(0, 0, 0, 0)
paint.color = color
canvas.drawRoundRect(rectF, roundPx, roundPx, paint)
paint.xfermode = PorterDuffXfermode(PorterDuff.Mode.SRC_IN)
canvas.drawBitmap(bitmap, rect, rect, paint)
return output
}
通過此代碼調用它
holder.itemFriendImage.setImageBitmap(ImageConverter.getRoundedCornerBitmap(bitmap,600))
**Jst Add this to your image Id and get the circuler image.**
imgUserProfile.setImageBitmap(getCircularCenterCropBitmap(bitmap, (int) (150 * denisty)));
Method:-
public void Bitmap getCircularCenterCropBitmap(Bitmap originalBmp, int diameter) {
Bitmap resizedBmp = BitmapUtils.getScaledCroppedBitmap(originalBmp, diameter, diameter);
return BitmapUtils.getRoundedCircularBitmap(resizedBmp, diameter / 2);
}
對於科特林:
private fun getCircularBitmap(bitmap: Bitmap): Bitmap? {
val output = Bitmap.createBitmap(
bitmap.width,
bitmap.height, Bitmap.Config.ARGB_8888
)
val canvas = Canvas(output)
val color = -0xbdbdbe
val paint = Paint()
val rect = Rect(0, 0, bitmap.width, bitmap.height)
paint.isAntiAlias = true
canvas.drawARGB(0, 0, 0, 0)
paint.color = color
canvas.drawCircle(
(bitmap.width / 2).toFloat(), (bitmap.height / 2).toFloat(), (
bitmap.width / 2).toFloat(), paint
)
paint.xfermode = PorterDuffXfermode(PorterDuff.Mode.SRC_IN)
canvas.drawBitmap(bitmap, rect, rect, paint)
return output
}
kotlin,放入 Ext.kt
private fun Bitmap.getCircledBitmap(): Bitmap {
val output = Bitmap.createBitmap(this.width, this.height, Bitmap.Config.ARGB_8888)
val canvas = Canvas(output)
val paint = Paint()
val rect = Rect(0, 0, this.width, this.height)
paint.isAntiAlias = true
canvas.drawARGB(0, 0, 0, 0)
canvas.drawCircle(this.width / 2f, this.height / 2f, this.width / 2f, paint)
paint.xfermode = PorterDuffXfermode(PorterDuff.Mode.SRC_IN)
canvas.drawBitmap(this, rect, rect, paint)
return output
}
不確定這是一個編程問題,但是...
最簡單的解決方案是使源位圖中的外部區域透明。 否則,您必須計算哪些像素在圓外,並相應地設置 alpha(alpha = 0 表示完全透明)。
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