Add draw_label_png visualization to README of examples

examples/instance_segmentation/.readme/draw_label_png_class.jpg

@@ -0,0 +1 @@
+../../semantic_segmentation/.readme/draw_label_png.jpg

examples/instance_segmentation/README.md

@@ -22,3 +22,14 @@ labelme data_annotated --labels labels.txt --nodata
 
 <img src="data_dataset_voc/JPEGImages/2011_000003.jpg" width="33%" /> <img src="data_dataset_voc/SegmentationClassVisualization/2011_000003.jpg" width="33%" /> <img src="data_dataset_voc/SegmentationObjectVisualization/2011_000003.jpg" width="33%" />  
 Fig 1. JPEG image (left), JPEG class label visualization (center), JPEG instance label visualization (right)
+
+
+Note that the reason why the label file is mostly black is it contains only very low label values (ex. `-1, 0, 4, 14`).  
+You can see the label PNG file by following.
+
+```bash
+labelme_draw_label_png data_dataset_voc/SegmentationClass/2011_000003.png   # left
+labelme_draw_label_png data_dataset_voc/SegmentationObject/2011_000003.png  # right
+```
+
+<img src=".readme/draw_label_png_class.jpg" width="33%" /> <img src=".readme/draw_label_png_object.jpg" width="33%" />

examples/semantic_segmentation/README.md

@@ -22,4 +22,13 @@ labelme data_annotated --labels labels.txt --nodata
 <img src="data_dataset_voc/JPEGImages/2011_000003.jpg" width="33%" /> <img src="data_dataset_voc/SegmentationClass/2011_000003.png" width="33%" /> <img src="data_dataset_voc/SegmentationClassVisualization/2011_000003.jpg" width="33%" />
 
 Fig 1. JPEG image (left), PNG label (center), JPEG label visualization (right)  
-*Note that the reason why the label file is mostly black is it contains only very low label values (ex. `-1, 0, 4, 14`).*
+
+
+Note that the reason why the label file is mostly black is it contains only very low label values (ex. `-1, 0, 4, 14`).  
+You can see the label PNG file by following.
+
+```bash
+labelme_draw_label_png data_dataset_voc/SegmentationClass/2011_000003.png
+```
+
+<img src=".readme/draw_label_png.jpg" width="33%" />