How to change text on bbox visualizer?

[nadyadtm]

I want to change the prediction text (ex: class 100% to class) in visualizer bbox. How can I change it in detectron2?

[sukjunhwang]

This is probably the function you should edit.

detectron2/detectron2/utils/visualizer.py

Line 230 in d1e0456

def _create_text_labels(classes, scores, class_names, is_crowd=None):

[nadyadtm]

Okay, I'm sorry I'm still newbie on Detectron2, so how do I run the code since visualizer is the default function in Detectron2? Do I have to re-install detectron again?

[sukjunhwang]

Hi @nadyadtm ,

If you are working on visualizing object detection or instance segmentation predictions on images, this function below is where Visualizer calls _create_text_labels.

detectron2/detectron2/utils/visualizer.py

Lines 383 to 398 in d1e0456

	def draw_instance_predictions(self, predictions):
	"""
	Draw instance-level prediction results on an image.
	Args:
	predictions (Instances): the output of an instance detection/segmentation
	model. Following fields will be used to draw:
	"pred_boxes", "pred_classes", "scores", "pred_masks" (or "pred_masks_rle").
	Returns:
	output (VisImage): image object with visualizations.
	"""
	boxes = predictions.pred_boxes if predictions.has("pred_boxes") else None
	scores = predictions.scores if predictions.has("scores") else None
	classes = predictions.pred_classes.tolist() if predictions.has("pred_classes") else None
	labels = _create_text_labels(classes, scores, self.metadata.get("thing_classes", None))

_create_text_labels simply outputs texts to be shown on top of bounding boxes.
So, if you want a different format of texts to be written, you can either fix that function directly, or create a class inheriting Visualizer and fix as whatever you want to.

[nadyadtm]

Sorry for the late reply

So that means I just call the function as usual after I change the function, right? No need to reinstall detectron, right? How I compile the changed function? I'm still confused about it

[sukjunhwang]

setup.py is mostly for environment configurations and installation of necessary libraries, so only changing the function would not need further compilation or reinstallation.

[nadyadtm]

Okay I'll try it, thanks for the answer