object detectionで物体検知したもののクラス名を出したい

Question

object detection APIを使って画像で出た物体の名前を画像と一緒に出したいと思っているのですが、どの変数をprint文で出力すればいいのかがわかりません。

In [0]:

For the sake of simplicity we will use only 2 images:

image1.jpg

image2.jpg

If you want to test the code with your images, just add path to the images to the TEST_IMAGE_PATHS.

PATH_TO_TEST_IMAGES_DIR = 'test_images'
TEST_IMAGE_PATHS = [ os.path.join(PATH_TO_TEST_IMAGES_DIR, 'image{}.jpg'.format(i)) for i in range(1, 3) ]

Size, in inches, of the output images.

IMAGE_SIZE = (12, 8)
In [0]:
def run_inference_for_single_image(image, graph):
with graph.as_default():
with tf.Session() as sess:
# Get handles to input and output tensors
ops = tf.get_default_graph().get_operations()
all_tensor_names = {output.name for op in ops for output in op.outputs}
tensor_dict = {}
for key in [
'num_detections', 'detection_boxes', 'detection_scores',
'detection_classes', 'detection_masks'
]:
tensor_name = key + ':0'
if tensor_name in all_tensor_names:
tensor_dict[key] = tf.get_default_graph().get_tensor_by_name(
tensor_name)
if 'detection_masks' in tensor_dict:
# The following processing is only for single image
detection_boxes = tf.squeeze(tensor_dict['detection_boxes'], [0])
detection_masks = tf.squeeze(tensor_dict['detection_masks'], [0])
# Reframe is required to translate mask from box coordinates to image coordinates and fit the image size.
real_num_detection = tf.cast(tensor_dict['num_detections'][0], tf.int32)
detection_boxes = tf.slice(detection_boxes, [0, 0], [real_num_detection, -1])
detection_masks = tf.slice(detection_masks, [0, 0, 0], [real_num_detection, -1, -1])
detection_masks_reframed = utils_ops.reframe_box_masks_to_image_masks(
detection_masks, detection_boxes, image.shape[0], image.shape[1])
detection_masks_reframed = tf.cast(
tf.greater(detection_masks_reframed, 0.5), tf.uint8)
# Follow the convention by adding back the batch dimension
tensor_dict['detection_masks'] = tf.expand_dims(
detection_masks_reframed, 0)
image_tensor = tf.get_default_graph().get_tensor_by_name('image_tensor:0')

  # Run inference
  output_dict = sess.run(tensor_dict,
                         feed_dict={image_tensor: np.expand_dims(image, 0)})

  # all outputs are float32 numpy arrays, so convert types as appropriate
  output_dict['num_detections'] = int(output_dict['num_detections'][0])
  output_dict['detection_classes'] = output_dict[
      'detection_classes'][0].astype(np.uint8)
  output_dict['detection_boxes'] = output_dict['detection_boxes'][0]
  output_dict['detection_scores'] = output_dict['detection_scores'][0]
  if 'detection_masks' in output_dict:
    output_dict['detection_masks'] = output_dict['detection_masks'][0]

return output_dict
In [0]:
for image_path in TEST_IMAGE_PATHS:
image = Image.open(image_path)

the array based representation of the image will be used later in order to prepare the

result image with boxes and labels on it.

image_np = load_image_into_numpy_array(image)

Expand dimensions since the model expects images to have shape: [1, None, None, 3]

image_np_expanded = np.expand_dims(image_np, axis=0)

Actual detection.

output_dict = run_inference_for_single_image(image_np, detection_graph)

Visualization of the results of a detection.

vis_util.visualize_boxes_and_labels_on_image_array(
image_np,
output_dict['detection_boxes'],
output_dict['detection_classes'],
output_dict['detection_scores'],
category_index,
instance_masks=output_dict.get('detection_masks'),
use_normalized_coordinates=True,
line_thickness=8)
plt.figure(figsize=IMAGE_SIZE)
plt.imshow(image_np)

Comments

[tiitoi]

動かしているコード等を追記できますか？

[quickquip]

せめて読めるように書いてほしい。最低限。

Answer 1

参考にしているのは、こちら の Notebook でしょうか。

ネットワークの出力に検出されたクラス ID の一覧が入っているので、それをラベル名に紐づけて表示すればよいです。

# クラス ID の一覧が入っている。
classes = output_dict['detection_classes']

# category_index にラベル名が入っている。
for cls_id in classes:
    print(category_index[cls_id]['name'])

visualize_boxes_and_labels_on_image_array() のコードが参考になるかと思います。