diff --git a/pkg/cloud-cover/k_means.go b/pkg/cloud-cover/k_means.go
index a31bff6..e750713 100644
--- a/pkg/cloud-cover/k_means.go
+++ b/pkg/cloud-cover/k_means.go
@@ -14,9 +14,10 @@ import (
 )
 
 const (
-	k         = 2   // 聚类数目，2表示云和非云
-	maxIters  = 100 // 最大迭代次数
-	tolerance = 1.0 // 聚类中心变化容忍度
+	k                   = 2   // 聚类数目，2表示云和非云
+	maxIters            = 100 // 最大迭代次数
+	tolerance           = 1.0 // 聚类中心变化容忍度
+	brightnessThreshold = 220 // 亮度阈值，值越大要求云更亮
 )
 
 type Pixel struct {
@@ -96,7 +97,15 @@ func computeCloudCoverByKMeans(img image.Image) float64 {
 	for y := 0; y < height; y++ {
 		for x := 0; x < width; x++ {
 			i := y*width + x
-			if assignments[i] == cloudCluster {
+			pixel := pixels[i]
+			// 计算亮度和颜色比值
+			brightness := (pixel.r + pixel.g + pixel.b) / 3
+			blueRedRatio := pixel.b / pixel.r
+			greenRedRatio := pixel.g / pixel.r
+
+			// 判断是否为云的条件：亮度大于阈值并且蓝色/红色比率较高
+			if (assignments[i] == cloudCluster && brightness > brightnessThreshold && blueRedRatio > 0.5) ||
+				(assignments[i] == cloudCluster && greenRedRatio > 0.8) {
 				outputImg.SetGray(x, y, color.Gray{Y: 255}) // 云区域
 				cloudPixels++
 			} else {