diff --git a/app/src/main/java/io/legado/app/help/ReadBookConfig.kt b/app/src/main/java/io/legado/app/help/ReadBookConfig.kt
index 540806f2c..0e0664565 100644
--- a/app/src/main/java/io/legado/app/help/ReadBookConfig.kt
+++ b/app/src/main/java/io/legado/app/help/ReadBookConfig.kt
@@ -92,7 +92,7 @@ object ReadBookConfig {
         val height = dm.heightPixels
         bg = durConfig.curBgDrawable(width, height).apply {
             if (this is BitmapDrawable) {
-                bgMeanColor = BitmapUtils.getMeanColor(bitmap)
+                bgMeanColor = bitmap.getMeanColor()
             } else if (this is ColorDrawable) {
                 bgMeanColor = color
             }
diff --git a/app/src/main/java/io/legado/app/help/ThemeConfig.kt b/app/src/main/java/io/legado/app/help/ThemeConfig.kt
index 0de2d2077..819284723 100644
--- a/app/src/main/java/io/legado/app/help/ThemeConfig.kt
+++ b/app/src/main/java/io/legado/app/help/ThemeConfig.kt
@@ -63,7 +63,7 @@ object ThemeConfig {
         if (bgCfg.second == 0) {
             return bgImage
         }
-        return BitmapUtils.stackBlur(bgImage, bgCfg.second.toFloat())
+        return bgImage.stackBlur(bgCfg.second.toFloat())
     }
 
     fun upConfig() {
diff --git a/app/src/main/java/io/legado/app/utils/BitmapUtils.kt b/app/src/main/java/io/legado/app/utils/BitmapUtils.kt
index 00fa6dc32..05b6872ea 100644
--- a/app/src/main/java/io/legado/app/utils/BitmapUtils.kt
+++ b/app/src/main/java/io/legado/app/utils/BitmapUtils.kt
@@ -1,3 +1,5 @@
+@file:Suppress("unused")
+
 package io.legado.app.utils
 
 import android.content.Context
@@ -14,7 +16,7 @@ import java.io.IOException
 import kotlin.math.*
 
 
-@Suppress("unused", "WeakerAccess", "MemberVisibilityCanBePrivate")
+@Suppress("WeakerAccess", "MemberVisibilityCanBePrivate")
 object BitmapUtils {
 
     /**
@@ -142,7 +144,6 @@ object BitmapUtils {
         return BitmapFactory.decodeStream(inputStream, null, op)
     }
 
-
     //图片不被压缩
     fun convertViewToBitmap(view: View, bitmapWidth: Int, bitmapHeight: Int): Bitmap {
         val bitmap = Bitmap.createBitmap(bitmapWidth, bitmapHeight, Config.ARGB_8888)
@@ -150,7 +151,6 @@ object BitmapUtils {
         return bitmap
     }
 
-
     /**
      * @param options
      * @param minSideLength
@@ -220,89 +220,90 @@ object BitmapUtils {
         }
     }
 
-    fun changeBitmapSize(bitmap: Bitmap, newWidth: Int, newHeight: Int): Bitmap {
+}
 
-        val width = bitmap.width
-        val height = bitmap.height
+fun Bitmap.changeSize(newWidth: Int, newHeight: Int): Bitmap {
+    val width = this.width
+    val height = this.height
 
-        //计算压缩的比率
-        var scaleWidth = newWidth.toFloat() / width
-        var scaleHeight = newHeight.toFloat() / height
+    //计算压缩的比率
+    var scaleWidth = newWidth.toFloat() / width
+    var scaleHeight = newHeight.toFloat() / height
 
-        if (scaleWidth > scaleHeight) {
-            scaleWidth = scaleHeight
-        } else {
-            scaleHeight = scaleWidth
-        }
+    if (scaleWidth > scaleHeight) {
+        scaleWidth = scaleHeight
+    } else {
+        scaleHeight = scaleWidth
+    }
 
-        //获取想要缩放的matrix
-        val matrix = Matrix()
-        matrix.postScale(scaleWidth, scaleHeight)
+    //获取想要缩放的matrix
+    val matrix = Matrix()
+    matrix.postScale(scaleWidth, scaleHeight)
 
-        //获取新的bitmap
-        return Bitmap.createBitmap(bitmap, 0, 0, width, height, matrix, true)
+    //获取新的bitmap
+    return Bitmap.createBitmap(this, 0, 0, width, height, matrix, true)
 
-    }
+}
 
-    /**
-     * 高斯模糊
-     */
-    fun stackBlur(srcBitmap: Bitmap?, radius: Float = 8f): Bitmap? {
-        if (srcBitmap == null) return null
-        val rs = RenderScript.create(appCtx)
-        val blurredBitmap = srcBitmap.copy(Config.ARGB_8888, true)
-
-        //分配用于渲染脚本的内存
-        val input = Allocation.createFromBitmap(
-            rs,
-            blurredBitmap,
-            Allocation.MipmapControl.MIPMAP_FULL,
-            Allocation.USAGE_SHARED
-        )
-        val output = Allocation.createTyped(rs, input.type)
-
-        //加载我们想要使用的特定脚本的实例。
-        val script = ScriptIntrinsicBlur.create(rs, Element.U8_4(rs))
-        script.setInput(input)
-
-        //设置模糊半径
-        script.setRadius(radius)
-
-        //启动 ScriptIntrinsicBlur
-        script.forEach(output)
-
-        //将输出复制到模糊的位图
-        output.copyTo(blurredBitmap)
-
-        return blurredBitmap
-    }
+/**
+ * 高斯模糊
+ */
+fun Bitmap.stackBlur(radius: Float = 8f): Bitmap? {
+    val rs = RenderScript.create(appCtx)
+    val blurredBitmap = this.copy(Config.ARGB_8888, true)
 
-    fun getMeanColor(bitmap: Bitmap): Int {
-        val width: Int = bitmap.width
-        val height: Int = bitmap.height
-        var pixel: Int
-        var pixelSumRed = 0
-        var pixelSumBlue = 0
-        var pixelSumGreen = 0
-        for (i in 0..99) {
-            for (j in 70..99) {
-                pixel = bitmap.getPixel(
-                    (i * width / 100.toFloat()).roundToInt(),
-                    (j * height / 100.toFloat()).roundToInt()
-                )
-                pixelSumRed += Color.red(pixel)
-                pixelSumGreen += Color.green(pixel)
-                pixelSumBlue += Color.blue(pixel)
-            }
+    //分配用于渲染脚本的内存
+    val input = Allocation.createFromBitmap(
+        rs,
+        blurredBitmap,
+        Allocation.MipmapControl.MIPMAP_FULL,
+        Allocation.USAGE_SHARED
+    )
+    val output = Allocation.createTyped(rs, input.type)
+
+    //加载我们想要使用的特定脚本的实例。
+    val script = ScriptIntrinsicBlur.create(rs, Element.U8_4(rs))
+    script.setInput(input)
+
+    //设置模糊半径
+    script.setRadius(radius)
+
+    //启动 ScriptIntrinsicBlur
+    script.forEach(output)
+
+    //将输出复制到模糊的位图
+    output.copyTo(blurredBitmap)
+
+    return blurredBitmap
+}
+
+/**
+ * 取平均色
+ */
+fun Bitmap.getMeanColor(): Int {
+    val width: Int = this.width
+    val height: Int = this.height
+    var pixel: Int
+    var pixelSumRed = 0
+    var pixelSumBlue = 0
+    var pixelSumGreen = 0
+    for (i in 0..99) {
+        for (j in 70..99) {
+            pixel = this.getPixel(
+                (i * width / 100.toFloat()).roundToInt(),
+                (j * height / 100.toFloat()).roundToInt()
+            )
+            pixelSumRed += Color.red(pixel)
+            pixelSumGreen += Color.green(pixel)
+            pixelSumBlue += Color.blue(pixel)
         }
-        val averagePixelRed = pixelSumRed / 3000
-        val averagePixelBlue = pixelSumBlue / 3000
-        val averagePixelGreen = pixelSumGreen / 3000
-        return Color.rgb(
-            averagePixelRed + 3,
-            averagePixelGreen + 3,
-            averagePixelBlue + 3
-        )
     }
-
+    val averagePixelRed = pixelSumRed / 3000
+    val averagePixelBlue = pixelSumBlue / 3000
+    val averagePixelGreen = pixelSumGreen / 3000
+    return Color.rgb(
+        averagePixelRed + 3,
+        averagePixelGreen + 3,
+        averagePixelBlue + 3
+    )
 }
diff --git a/app/src/main/java/io/legado/app/utils/QRCodeUtils.kt b/app/src/main/java/io/legado/app/utils/QRCodeUtils.kt
index 2a42839d6..a6a8747a0 100644
--- a/app/src/main/java/io/legado/app/utils/QRCodeUtils.kt
+++ b/app/src/main/java/io/legado/app/utils/QRCodeUtils.kt
@@ -182,7 +182,7 @@ object QRCodeUtils {
         hints: Map<DecodeHintType?, Any?> = DecodeFormatManager.ALL_HINTS
     ): Result? {
         if (bitmap.width > reqWidth || bitmap.height > reqHeight) {
-            val bm = BitmapUtils.changeBitmapSize(bitmap, reqWidth, reqHeight)
+            val bm = bitmap.changeSize(reqWidth, reqHeight)
             return parseCodeResult(getRGBLuminanceSource(bm), hints)
         }
         return parseCodeResult(getRGBLuminanceSource(bitmap), hints)