diff --git a/carpad_recog/main.py b/carpad_recog/main.py
index afb999423cf2eb2039b9283518326b9cda7e6d55..2bcc4f11a67b9df477ed739a88737a1fbd238129 100755
--- a/carpad_recog/main.py
+++ b/carpad_recog/main.py
@@ -106,9 +106,9 @@ def Cardseg(rois, colors):
                     break
                 else:
                     cur_dis += wave[1] - wave[0]
-            if i > 0:
-                wave = (wave_peaks[0][0], wave_peaks[i][1])
-                wave_peaks = wave_peaks[i+1:]
+            if j > 0:
+                wave = (wave_peaks[0][0], wave_peaks[j][1])
+                wave_peaks = wave_peaks[j+1:]
                 wave_peaks.insert(0, wave)
             
             point = wave_peaks[2]