diff --git a/exp/kerokero/prepare_data.py b/exp/kerokero/prepare_data.py
--- a/exp/kerokero/prepare_data.py
+++ b/exp/kerokero/prepare_data.py
@@ -37,7 +37,7 @@ class Sample:
 			m=np.matmul(mi,m)
 		m=np.matmul(self._computeCrop(m),m)
 		img=cv.warpPerspective(self.img,m,(self.SIDE,self.SIDE))
-		img=np.float32(img)/128-1
+		img=np.uint8(img)
 		grid=Corners(c.transform(m) for c in self.grid)
 		grid=list(map(lambda p: list(2*p/self.SIDE-EPoint(1,1)), grid))
 		return (img,grid)
@@ -108,8 +108,8 @@ def loadDataset(root):
 	labels=[labels[k] for k in keys]
 	m=int(n*trainRatio)
 	return (
-		(np.float32(images[:m]),np.float32(labels[:m])),
-		(np.float32(images[m:]),np.float32(labels[m:]))
+		(np.uint8(images[:m]),np.float32(labels[:m])),
+		(np.uint8(images[m:]),np.float32(labels[m:]))
 	)