--- a
+++ b/darkflow/cython_utils/nms.pyx
@@ -0,0 +1,131 @@
+import numpy as np
+cimport numpy as np
+cimport cython
+from libc.math cimport exp
+from ..utils.box import BoundBox
+
+
+
+#OVERLAP
+@cython.boundscheck(False) # turn off bounds-checking for entire function
+@cython.wraparound(False)  # turn off negative index wrapping for entire function
+@cython.cdivision(True)
+cdef float overlap_c(float x1, float w1 , float x2 , float w2):
+    cdef:
+        float l1,l2,left,right
+    l1 = x1 - w1 /2.
+    l2 = x2 - w2 /2.
+    left = max(l1,l2)
+    r1 = x1 + w1 /2.
+    r2 = x2 + w2 /2.
+    right = min(r1, r2)
+    return right - left;
+
+#BOX INTERSECTION
+@cython.boundscheck(False) # turn off bounds-checking for entire function
+@cython.wraparound(False)  # turn off negative index wrapping for entire function
+@cython.cdivision(True)
+cdef float box_intersection_c(float ax, float ay, float aw, float ah, float bx, float by, float bw, float bh):
+    cdef:
+        float w,h,area
+    w = overlap_c(ax, aw, bx, bw)
+    h = overlap_c(ay, ah, by, bh)
+    if w < 0 or h < 0: return 0
+    area = w * h
+    return area
+
+#BOX UNION
+@cython.boundscheck(False) # turn off bounds-checking for entire function
+@cython.wraparound(False)  # turn off negative index wrapping for entire function
+@cython.cdivision(True)
+cdef float box_union_c(float ax, float ay, float aw, float ah, float bx, float by, float bw, float bh):
+    cdef:
+        float i,u
+    i = box_intersection_c(ax, ay, aw, ah, bx, by, bw, bh)
+    u = aw * ah + bw * bh -i
+    return u
+
+
+#BOX IOU
+@cython.boundscheck(False) # turn off bounds-checking for entire function
+@cython.wraparound(False)  # turn off negative index wrapping for entire function
+@cython.cdivision(True)
+cdef float box_iou_c(float ax, float ay, float aw, float ah, float bx, float by, float bw, float bh):
+    return box_intersection_c(ax, ay, aw, ah, bx, by, bw, bh) / box_union_c(ax, ay, aw, ah, bx, by, bw, bh);
+
+
+
+
+#NMS
+@cython.boundscheck(False) # turn off bounds-checking for entire function
+@cython.wraparound(False)  # turn off negative index wrapping for entire function
+@cython.cdivision(True)
+cdef NMS(float[:, ::1] final_probs , float[:, ::1] final_bbox):
+    cdef list boxes = list()
+    cdef set indices = set()
+    cdef:
+        np.intp_t pred_length,class_length,class_loop,index,index2
+
+  
+    pred_length = final_bbox.shape[0]
+    class_length = final_probs.shape[1]
+    for class_loop in range(class_length):
+        for index in range(pred_length):
+            if final_probs[index,class_loop] == 0: continue
+            for index2 in range(index+1,pred_length):
+                if final_probs[index2,class_loop] == 0: continue
+                if index==index2 : continue
+                if box_iou_c(final_bbox[index,0],final_bbox[index,1],final_bbox[index,2],final_bbox[index,3],final_bbox[index2,0],final_bbox[index2,1],final_bbox[index2,2],final_bbox[index2,3]) >= 0.4:
+                    if final_probs[index2,class_loop] > final_probs[index, class_loop] :
+                        final_probs[index, class_loop] =0
+                        break
+                    final_probs[index2,class_loop]=0
+            
+            if index not in indices:
+                bb=BoundBox(class_length)
+                bb.x = final_bbox[index, 0]
+                bb.y = final_bbox[index, 1]
+                bb.w = final_bbox[index, 2]
+                bb.h = final_bbox[index, 3]
+                bb.c = final_bbox[index, 4]
+                bb.probs = np.asarray(final_probs[index,:])
+                boxes.append(bb)
+                indices.add(index)
+    return boxes
+
+# cdef NMS(float[:, ::1] final_probs , float[:, ::1] final_bbox):
+#     cdef list boxes = list()
+#     cdef:
+#         np.intp_t pred_length,class_length,class_loop,index,index2, i, j
+
+  
+#     pred_length = final_bbox.shape[0]
+#     class_length = final_probs.shape[1]
+
+#     for class_loop in range(class_length):
+#         order = np.argsort(final_probs[:,class_loop])[::-1]
+#         # First box
+#         for i in range(pred_length):
+#             index = order[i]
+#             if final_probs[index, class_loop] == 0.: 
+#                 continue
+#             # Second box
+#             for j in range(i+1, pred_length):
+#                 index2 = order[j]
+#                 if box_iou_c(
+#                     final_bbox[index,0],final_bbox[index,1],
+#                     final_bbox[index,2],final_bbox[index,3],
+#                     final_bbox[index2,0],final_bbox[index2,1],
+#                     final_bbox[index2,2],final_bbox[index2,3]) >= 0.4:
+#                     final_probs[index2, class_loop] = 0.
+                    
+#             bb = BoundBox(class_length)
+#             bb.x = final_bbox[index, 0]
+#             bb.y = final_bbox[index, 1]
+#             bb.w = final_bbox[index, 2]
+#             bb.h = final_bbox[index, 3]
+#             bb.c = final_bbox[index, 4]
+#             bb.probs = np.asarray(final_probs[index,:])
+#             boxes.append(bb)
+  
+#     return boxes