fix_roi_transform_bug (#19785)

paddle/fluid/operators/detection/roi_perspective_transform_op.cc

@@ -128,11 +128,11 @@ void get_transform_matrix(const int transformed_width,
   T estimated_width = (len1 + len3) / 2.0;
 
   // Get the normalized height and normalized width
-  int normalized_height = transformed_height;
+  int normalized_height = std::max(2, transformed_height);
   int normalized_width =
       std::round(estimated_width * (normalized_height - 1) / estimated_height) +
       1;
-  normalized_width = std::min(normalized_width, transformed_width);
+  normalized_width = std::max(2, std::min(normalized_width, transformed_width));
 
   T dx1 = x1 - x2;
   T dx2 = x3 - x2;
@@ -141,9 +141,9 @@ void get_transform_matrix(const int transformed_width,
   T dy2 = y3 - y2;
   T dy3 = y0 - y1 + y2 - y3;
 
-  matrix[6] = (dx3 * dy2 - dx2 * dy3) / (dx1 * dy2 - dx2 * dy1) /
+  matrix[6] = (dx3 * dy2 - dx2 * dy3) / (dx1 * dy2 - dx2 * dy1 + 1e-5) /
               (normalized_width - 1);
-  matrix[7] = (dx1 * dy3 - dx3 * dy1) / (dx1 * dy2 - dx2 * dy1) /
+  matrix[7] = (dx1 * dy3 - dx3 * dy1) / (dx1 * dy2 - dx2 * dy1 + 1e-5) /
               (normalized_height - 1);
   matrix[8] = 1;
 

paddle/fluid/operators/detection/roi_perspective_transform_op.cu

@@ -242,10 +242,10 @@ __device__ void get_transform_matrix(const int transformed_width,
   T estimated_width = (len1 + len3) / 2.0;
 
   // Get the normalized height and normalized width
-  int normalized_height = transformed_height;
+  int normalized_height = max(2, transformed_height);
   int normalized_width =
       round(estimated_width * (normalized_height - 1) / estimated_height) + 1;
-  normalized_width = min(normalized_width, transformed_width);
+  normalized_width = max(2, min(normalized_width, transformed_width));
 
   T dx1 = x1 - x2;
   T dx2 = x3 - x2;
@@ -254,9 +254,9 @@ __device__ void get_transform_matrix(const int transformed_width,
   T dy2 = y3 - y2;
   T dy3 = y0 - y1 + y2 - y3;
 
-  matrix[6] = (dx3 * dy2 - dx2 * dy3) / (dx1 * dy2 - dx2 * dy1) /
+  matrix[6] = (dx3 * dy2 - dx2 * dy3) / (dx1 * dy2 - dx2 * dy1 + 1e-5) /
               (normalized_width - 1);
-  matrix[7] = (dx1 * dy3 - dx3 * dy1) / (dx1 * dy2 - dx2 * dy1) /
+  matrix[7] = (dx1 * dy3 - dx3 * dy1) / (dx1 * dy2 - dx2 * dy1 + 1e-5) /
               (normalized_height - 1);
   matrix[8] = 1;
 

python/paddle/fluid/tests/unittests/test_roi_perspective_transform_op.py

@@ -87,10 +87,10 @@ def get_transform_matrix(transformed_width, transformed_height, roi_x, roi_y):
     estimated_height = (len2 + len4) / 2.0
     estimated_width = (len1 + len3) / 2.0
 
-    normalized_height = transformed_height
+    normalized_height = max(2, transformed_height)
     normalized_width = round(estimated_width *
                              (normalized_height - 1) / estimated_height) + 1
-    normalized_width = min(normalized_width, transformed_width)
+    normalized_width = max(2, min(normalized_width, transformed_width))
 
     dx1 = x1 - x2
     dx2 = x3 - x2
@@ -99,9 +99,9 @@ def get_transform_matrix(transformed_width, transformed_height, roi_x, roi_y):
     dy2 = y3 - y2
     dy3 = y0 - y1 + y2 - y3
     matrix = np.zeros([9])
-    matrix[6] = (dx3 * dy2 - dx2 * dy3) / (dx1 * dy2 - dx2 * dy1) / (
+    matrix[6] = (dx3 * dy2 - dx2 * dy3) / (dx1 * dy2 - dx2 * dy1 + 1e-5) / (
         normalized_width - 1)
-    matrix[7] = (dx1 * dy3 - dx3 * dy1) / (dx1 * dy2 - dx2 * dy1) / (
+    matrix[7] = (dx1 * dy3 - dx3 * dy1) / (dx1 * dy2 - dx2 * dy1 + 1e-5) / (
         normalized_height - 1)
     matrix[8] = 1