fix nms implentation of cpu (#1244)

mmcv/ops/csrc/onnxruntime/cpu/nms.cpp

@@ -88,7 +88,7 @@ void NmsKernel::Compute(OrtKernelContext *context) {
       auto h = std::max(0.f, yy2 - yy1 + offset);
       auto inter = w * h;
       auto ovr = inter / (iarea + areas[j] - inter);
-      if (ovr >= iou_threshold) select[_j] = false;
+      if (ovr > iou_threshold) select[_j] = false;
     }
   }
   std::vector<int64_t> res_order;

mmcv/ops/csrc/parrots/nms.cpp

@@ -55,7 +55,7 @@ Tensor nms_cpu(Tensor boxes, Tensor scores, float iou_threshold, int offset) {
       auto h = std::max(0.f, yy2 - yy1 + offset);
       auto inter = w * h;
       auto ovr = inter / (iarea + areas[j] - inter);
-      if (ovr >= iou_threshold) select[_j] = false;
+      if (ovr > iou_threshold) select[_j] = false;
     }
   }
   return order_t.masked_select(select_t);

mmcv/ops/csrc/pytorch/nms.cpp

@@ -55,7 +55,7 @@ Tensor nms_cpu(Tensor boxes, Tensor scores, float iou_threshold, int offset) {
       auto h = std::max(0.f, yy2 - yy1 + offset);
       auto inter = w * h;
       auto ovr = inter / (iarea + areas[j] - inter);
-      if (ovr >= iou_threshold) select[_j] = false;
+      if (ovr > iou_threshold) select[_j] = false;
     }
   }
   return order_t.masked_select(select_t);