Android高斯模糊在java层面上的两种实现方式

第一种是依赖于support-v8的实现如下

import android.content.Context;import android.graphics.Bitmap;import android.graphics.Canvas;import android.graphics.Color;import android.graphics.Paint;import android.graphics.PorterDuff;import android.graphics.PorterDuffColorFilter;import android.support.annotation.FloatRange;import android.support.v8.renderscript.Allocation;import android.support.v8.renderscript.Element;import android.support.v8.renderscript.RenderScript;import android.support.v8.renderscript.ScriptIntrinsicBlur;import com.bumptech.glide.load.engine.bitmap_recycle.BitmapPool;import com.bumptech.glide.load.resource.bitmap.BitmapTransformation;import com.bumptech.glide.request.target.Target;/** * Georgia Blur Transformation * <p> * @author Ligboy.Liu [e-mail]. */public class BlurTransformation extends BitmapTransformation {    private static final String ID = "org.ligboy.glide.BlurTransformation";    public static final float DEFAULT_RADIUS = 25.0f;    public static final float MAX_RADIUS = 25.0f;    private static final float DEFAULT_SAMPLING = 1.0f;    private Context mContext;    private float mSampling = DEFAULT_SAMPLING;    private float mRadius;    private int mColor;    public static class Builder {        private Context mContext;        private float mRadius = DEFAULT_RADIUS;        private int mColor = Color.TRANSPARENT;        public Builder(Context mContext) {            this.mContext = mContext;        }        public float getRadius() {            return mRadius;        }        public Builder setRadius(float radius) {            mRadius = radius;            return this;        }        public int getColor() {            return mColor;        }        public Builder setColor(int color) {            mColor = color;            return this;        }        public BlurTransformation build() {            return new BlurTransformation(mContext, mRadius, mColor);        }    }    /**     *     * @param context Context     * @param radius The blur's radius.     * @param color The color filter for blurring.     */    public BlurTransformation(Context context, @FloatRange(from = 0.0f) float radius, int color) {        super(context);        mContext = context;        if (radius > MAX_RADIUS) {            mSampling = radius / 25.0f;            mRadius = MAX_RADIUS;        } else {            mRadius = radius;        }        mColor = color;    }    /**     *     * @param context Context     * @param radius The blur's radius.     */    public BlurTransformation(Context context, @FloatRange(from = 0.0f) float radius) {        this(context, radius, Color.TRANSPARENT);    }    public BlurTransformation(Context context) {        this(context, DEFAULT_RADIUS);    }    /**     * Transforms the given {@link Bitmap} based on the given dimensions and returns the transformed     * result.     * <p/>     * <p>     * The provided Bitmap, toTransform, should not be recycled or returned to the pool. Glide will automatically     * recycle and/or reuse toTransform if the transformation returns a different Bitmap. Similarly implementations     * should never recycle or return Bitmaps that are returned as the result of this method. Recycling or returning     * the provided and/or the returned Bitmap to the pool will lead to a variety of runtime exceptions and drawing     * errors. See #408 for an example. If the implementation obtains and discards intermediate Bitmaps, they may     * safely be returned to the BitmapPool and/or recycled.     * </p>     * <p/>     * <p>     * outWidth and outHeight will never be {@link Target#SIZE_ORIGINAL}, this     * class converts them to be the size of the Bitmap we're going to transform before calling this method.     * </p>     *     * @param pool        A {@link BitmapPool} that can be used to obtain and     *                    return intermediate {@link Bitmap}s used in this transformation. For every     *                    {@link Bitmap} obtained from the pool during this transformation, a     *                    {@link Bitmap} must also be returned.     * @param toTransform The {@link Bitmap} to transform.     * @param outWidth    The ideal width of the transformed bitmap (the transformed width does not need to match exactly).     * @param outHeight   The ideal height of the transformed bitmap (the transformed heightdoes not need to match     */    @Override    protected Bitmap transform(BitmapPool pool, Bitmap toTransform, int outWidth, int outHeight) {        boolean needScaled = mSampling == DEFAULT_SAMPLING;        int originWidth = toTransform.getWidth();        int originHeight = toTransform.getHeight();        int width, height;        if (needScaled) {            width = originWidth;            height = originHeight;        } else {            width = (int) (originWidth / mSampling);            height = (int) (originHeight / mSampling);        }        //find a re-use bitmap        Bitmap bitmap = pool.get(width, height, Bitmap.Config.ARGB_8888);        if (bitmap == null) {            bitmap = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);        }        Canvas canvas = new Canvas(bitmap);        if (mSampling != DEFAULT_SAMPLING) {            canvas.scale(1 / mSampling, 1 / mSampling);        }        Paint paint = new Paint();        paint.setFlags(Paint.FILTER_BITMAP_FLAG | Paint.ANTI_ALIAS_FLAG);        PorterDuffColorFilter filter =                new PorterDuffColorFilter(mColor, PorterDuff.Mode.SRC_ATOP);        paint.setColorFilter(filter);        canvas.drawBitmap(toTransform, 0, 0, paint);// TIPS: Glide will take care of returning our original Bitmap to the BitmapPool for us,// we needn't to recycle it.//        toTransform.recycle();  <--- Just for tips. by Ligboy        RenderScript rs = RenderScript.create(mContext);        Allocation input = Allocation.createFromBitmap(rs, bitmap, Allocation.MipmapControl.MIPMAP_NONE,                Allocation.USAGE_SCRIPT);        Allocation output = Allocation.createTyped(rs, input.getType());        ScriptIntrinsicBlur blur = ScriptIntrinsicBlur.create(rs, Element.U8_4(rs));        blur.setInput(input);        blur.setRadius(mRadius);        blur.forEach(output);        output.copyTo(bitmap);        rs.destroy();        if (needScaled) {            return bitmap;        } else {            Bitmap scaled = Bitmap.createScaledBitmap(bitmap, originWidth, originHeight, true);            bitmap.recycle();            return scaled;        }    }    /**     * A method to get a unique identifier for this particular transformation that can be used as part of a cache key.     * The fully qualified class name for this class is appropriate if written out, but getClass().getName() is not     * because the name may be changed by proguard.     * <p/>     * <p>     * If this transformation does not affect the data that will be stored in cache, returning an empty string here     * is acceptable.     * </p>     *     * @return A string that uniquely identifies this transformation.     */    @Override    public String getId() {        StringBuilder sb = new StringBuilder(ID);        sb.append('-').append(mRadius).append('-').append(mColor);        return sb.toString();    }}

然后在build.gradle上的defaultConfig上配置如下两排代码

defaultConfig {

        renderscriptTargetApi 20
        renderscriptSupportModeEnabled true

}

在activity里面用glide加载网络图片并模糊

Glide.with(Context).load(url).asBitmap().transform(new BlurTransformation(Context, 25)).into(ivbg);

这是一种方法。

第二种

package com.wbkj.artmss.Weight;import android.content.Context;import android.graphics.Bitmap;import android.graphics.Canvas;import android.graphics.Color;import android.graphics.Paint;import android.graphics.PorterDuff;import android.graphics.PorterDuffColorFilter;import android.renderscript.Allocation;import android.renderscript.Element;import android.renderscript.RenderScript;import android.renderscript.ScriptIntrinsicBlur;import android.support.annotation.FloatRange;import com.bumptech.glide.load.engine.bitmap_recycle.BitmapPool;import com.bumptech.glide.load.resource.bitmap.BitmapTransformation;import com.bumptech.glide.request.target.Target;public class FastBlur extends BitmapTransformation {    private static final String ID = "org.ligboy.glide.BlurTransformation";    public static final float DEFAULT_RADIUS = 25.0f;    public static final float MAX_RADIUS = 25.0f;    private static final float DEFAULT_SAMPLING = 1.0f;    private Context mContext;    private float mSampling = DEFAULT_SAMPLING;    private float mRadius;    private int mColor;    public static class Builder {        private Context mContext;        private float mRadius = DEFAULT_RADIUS;        private int mColor = Color.TRANSPARENT;        public Builder(Context mContext) {            this.mContext = mContext;        }        public float getRadius() {            return mRadius;        }        public Builder setRadius(float radius) {            mRadius = radius;            return this;        }        public int getColor() {            return mColor;        }        public Builder setColor(int color) {            mColor = color;            return this;        }        public FastBlur build() {            return new FastBlur(mContext, mRadius, mColor);        }    }    /**     * @param context Context     * @param radius  The blur's radius.     * @param color   The color filter for blurring.     */    public FastBlur(Context context, @FloatRange(from = 0.0f) float radius, int color) {        super(context);        mContext = context;        if (radius > MAX_RADIUS) {            mSampling = radius / 25.0f;            mRadius = MAX_RADIUS;        } else {            mRadius = radius;        }        mColor = color;    }    /**     * @param context Context     * @param radius  The blur's radius.     */    public FastBlur(Context context, @FloatRange(from = 0.0f) float radius) {        this(context, radius, Color.TRANSPARENT);    }    public FastBlur(Context context) {        this(context, DEFAULT_RADIUS);    }    /**     * Transforms the given {@link Bitmap} based on the given dimensions and returns the transformed     * result.     * <p/>     * <p>     * The provided Bitmap, toTransform, should not be recycled or returned to the pool. Glide will automatically     * recycle and/or reuse toTransform if the transformation returns a different Bitmap. Similarly implementations     * should never recycle or return Bitmaps that are returned as the result of this method. Recycling or returning     * the provided and/or the returned Bitmap to the pool will lead to a variety of runtime exceptions and drawing     * errors. See #408 for an example. If the implementation obtains and discards intermediate Bitmaps, they may     * safely be returned to the BitmapPool and/or recycled.     * </p>     * <p/>     * <p>     * outWidth and outHeight will never be {@link Target#SIZE_ORIGINAL}, this     * class converts them to be the size of the Bitmap we're going to transform before calling this method.     * </p>     *     * @param pool        A {@link BitmapPool} that can be used to obtain and     *                    return intermediate {@link Bitmap}s used in this transformation. For every     *                    {@link Bitmap} obtained from the pool during this transformation, a     *                    {@link Bitmap} must also be returned.     * @param toTransform The {@link Bitmap} to transform.     * @param outWidth    The ideal width of the transformed bitmap (the transformed width does not need to match exactly).     * @param outHeight   The ideal height of the transformed bitmap (the transformed heightdoes not need to match     */    @Override    protected Bitmap transform(BitmapPool pool, Bitmap toTransform, int outWidth, int outHeight) {        boolean needScaled = mSampling == DEFAULT_SAMPLING;        int originWidth = toTransform.getWidth();        int originHeight = toTransform.getHeight();        int width, height;        if (needScaled) {            width = originWidth;            height = originHeight;        } else {            width = (int) (originWidth / mSampling);            height = (int) (originHeight / mSampling);        }        //find a re-use bitmap        Bitmap bitmap = pool.get(width, height, Bitmap.Config.ARGB_8888);        if (bitmap == null) {            bitmap = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);        }        Canvas canvas = new Canvas(bitmap);        if (mSampling != DEFAULT_SAMPLING) {            canvas.scale(1 / mSampling, 1 / mSampling);        }        Paint paint = new Paint();        paint.setFlags(Paint.FILTER_BITMAP_FLAG | Paint.ANTI_ALIAS_FLAG);        PorterDuffColorFilter filter =                new PorterDuffColorFilter(mColor, PorterDuff.Mode.SRC_ATOP);        paint.setColorFilter(filter);        canvas.drawBitmap(toTransform, 0, 0, paint);// TIPS: Glide will take care of returning our original Bitmap to the BitmapPool for us,// we needn't to recycle it.//        toTransform.recycle();  <--- Just for tips. by Ligboy        RenderScript rs = RenderScript.create(mContext);        Allocation input = Allocation.createFromBitmap(rs, bitmap, Allocation.MipmapControl.MIPMAP_NONE,                Allocation.USAGE_SCRIPT);        Allocation output = Allocation.createTyped(rs, input.getType());        ScriptIntrinsicBlur blur = ScriptIntrinsicBlur.create(rs, Element.U8_4(rs));        blur.setInput(input);        blur.setRadius(mRadius);        blur.forEach(output);        output.copyTo(bitmap);        rs.destroy();        if (needScaled) {            return bitmap;        } else {            Bitmap scaled = Bitmap.createScaledBitmap(bitmap, originWidth, originHeight, true);            bitmap.recycle();            return scaled;        }    }    /**     * A method to get a unique identifier for this particular transformation that can be used as part of a cache key.     * The fully qualified class name for this class is appropriate if written out, but getClass().getName() is not     * because the name may be changed by proguard.     * <p/>     * <p>     * If this transformation does not affect the data that will be stored in cache, returning an empty string here     * is acceptable.     * </p>     *     * @return A string that uniquely identifies this transformation.     */    @Override    public String getId() {        StringBuilder sb = new StringBuilder(ID);        sb                .append('-').append(mRadius)                .append('-').append(mColor);        return sb.toString();    }}

第二种方法只要sdk版本大于17就可行用法也是一样

Glide.with(this).load(url).asBitmap().transform(new FastBlur(this, 25)).into(ivbg);

minSdkVersion 17

效果如图