Update README.md

README.md

@@ -83,7 +83,7 @@ approach provides reliable object detection and classification
 results in maritime environments.
 
 
-![Image description](fig4.jpg)
+![Image description](figure4.jpg)
 
 Fig. 4. Mapping the detected objects by all sensors in Fig. 2 on (a) radar coordinates and (b) RGB camera image. ’F’ box in the bottom left corner of
 each figure indicates the location of the ferry.