diff --git a/deploy/cpp/include/preprocess_op.h b/deploy/cpp/include/preprocess_op.h
index 1e6c8844e8c25345cc60085e8bea87b256a9f9d9..bb2d0ca3eea6b58dc9ca064fb29cd3ea30acbb74 100644
--- a/deploy/cpp/include/preprocess_op.h
+++ b/deploy/cpp/include/preprocess_op.h
@@ -39,6 +39,8 @@ class ImageBlob {
   std::vector<float> ori_im_size_f_;
   // Evaluation image width and height
   std::vector<float>  eval_im_size_f_;
+  // Scale factor for image size to origin image size
+  std::vector<float> scale_factor_f_;
 };
 
 // Abstraction of preprocessing opration class
diff --git a/deploy/cpp/src/object_detector.cc b/deploy/cpp/src/object_detector.cc
index 7b660127d9433714c65a52245f4bf38006d06720..c8aaedeb4dafa104a4227c24e46cc9d9d9176091 100644
--- a/deploy/cpp/src/object_detector.cc
+++ b/deploy/cpp/src/object_detector.cc
@@ -140,7 +140,7 @@ void ObjectDetector::Postprocess(
     int ymax = (output_data_[5 + j * 6] * rh);
     int wd = xmax - xmin;
     int hd = ymax - ymin;
-    if (score > threshold_) {
+    if (score > threshold_ && class_id > -1) {
       ObjectResult result_item;
       result_item.rect = {xmin, xmax, ymin, ymax};
       result_item.class_id = class_id;
@@ -172,6 +172,9 @@ void ObjectDetector::Predict(const cv::Mat& im,
     } else if (tensor_name == "im_shape") {
       in_tensor->Reshape({1, 3});
       in_tensor->copy_from_cpu(inputs_.ori_im_size_f_.data());
+    } else if (tensor_name == "scale_factor") {
+      in_tensor->Reshape({1, 4});
+      in_tensor->copy_from_cpu(inputs_.scale_factor_f_.data());
     }
   }
   // Run predictor
diff --git a/deploy/cpp/src/preprocess_op.cc b/deploy/cpp/src/preprocess_op.cc
index b3bc27528affe0ba4f83cd247daa59aa20d1cd25..f572bac74039767a8a79747dab67ea504bd1d273 100644
--- a/deploy/cpp/src/preprocess_op.cc
+++ b/deploy/cpp/src/preprocess_op.cc
@@ -78,6 +78,12 @@ void Resize::Run(cv::Mat* im, ImageBlob* data) {
     static_cast<float>(im->cols),
     resize_scale.first
   };
+  data->scale_factor_f_ = {
+    resize_scale.first,
+    resize_scale.second,
+    resize_scale.first,
+    resize_scale.second
+  };
 }
 
 std::pair<float, float> Resize::GenerateScale(const cv::Mat& im) {
diff --git a/tools/infer.py b/tools/infer.py
index f7783d20b5e892aea5ac7fabbe16707597548184..034e33e66a4a422a70bf5d746d4c472618baa5e1 100644
--- a/tools/infer.py
+++ b/tools/infer.py
@@ -178,6 +178,8 @@ def main():
             for k, v in zip(keys, outs)
         }
         logger.info('Infer iter {}'.format(iter_id))
+        if 'TTFNet' in cfg.architecture:
+            res['bbox'][1].append([len(res['bbox'][0])])
 
         bbox_results = None
         mask_results = None
@@ -256,4 +258,4 @@ if __name__ == '__main__':
         default="vdl_log_dir/image",
         help='VisualDL logging directory for image.')
     FLAGS = parser.parse_args()
-    main()
\ No newline at end of file
+    main()