ObjClassCollection

class supervisely_lib.annotation.obj_class_collection.ObjClassCollection(items: Optional[dict] = None)

Bases: supervisely_lib.collection.key_indexed_collection.KeyIndexedCollection, supervisely_lib.io.json.JsonSerializable

Collection with ObjClass instances. ObjClassCollection object is immutable.

Raises

DuplicateKeyError if instance with given name already exist

Usage example

# Create ObjClass (see class ObjClass for more information)
class_lemon = sly.ObjClass('lemon', sly.Rectangle)
class_kiwi = sly.ObjClass('kiwi', sly.Bitmap)

class_arr = [class_lemon, class_kiwi]

# Create ObjClassCollection from ObjClasses
classes = sly.ObjClassCollection(class_arr)

# Add items to ObjClassCollection
class_potato = sly.ObjClass('potato', sly.Bitmap)

# Remember that ObjClassCollection is immutable, and we need to assign new instance of ObjClassCollection to a new variable
classes = classes.add(class_potato)

# You can also add multiple items to collection
class_cabbage = sly.ObjClass('cabbage', sly.Rectangle)
class_carrot = sly.ObjClass('carrot', sly.Bitmap)
class_turnip = sly.ObjClass('turnip', sly.Polygon)

classes = classes.add_items([class_cabbage, class_carrot, class_turnip])

# Has key, checks if given key exist in collection
classes.has_key("cabbage")
# Output: True

# Intersection, finds intersection of given list of instances with collection items
class_dog = sly.ObjClass('dog', sly.Rectangle)
class_cat = sly.ObjClass('cat', sly.Rectangle)
class_turtle = sly.ObjClass('turtle', sly.Rectangle)

classes_animals = sly.ObjClassCollection([class_dog, class_cat, class_turtle])

classes_intersections = classes.intersection(classes_animals)
print(classes_intersections.to_json())
# Output: []

# Let's add the potato ObjClass from another collection and compare them again
classes_animals = classes_animals.add(class_potato)

classes_intersections = classes.intersection(classes_animals)
print(classes_intersections.to_json())
# Output: [
#     {
#         "title":"potato",
#         "shape":"bitmap",
#         "color":"#8A570F",
#         "geometry_config":{},
#         "hotkey":""
#     }
# ]

# Difference, finds difference between collection and given list of ObjClass or ObjClassCollection
class_car = sly.ObjClass('car', sly.Rectangle)
class_bicycle = sly.ObjClass('bicycle', sly.Rectangle)

classes_vehicles = sly.ObjClassCollection([class_car, class_bicycle])

class_pedestrian = sly.ObjClass('pedestrian', sly.Rectangle)
class_road = sly.ObjClass('road', sly.Rectangle)

difference = classes_vehicles.difference([class_pedestrian, class_road])
print(difference.to_json())
# Output: [
#     {
#         "title":"car",
#         "shape":"rectangle",
#         "color":"#8A0F3B",
#         "geometry_config":{},
#         "hotkey":""
#     },
#     {
#         "title":"bicycle",
#         "shape":"rectangle",
#         "color":"#0F8A1F",
#         "geometry_config":{},
#         "hotkey":""
#     }
# ]

# Merge, merges collection and given list of ObjClasses
c_1 = sly.ObjClassCollection([class_car, class_bicycle])
c_2 = sly.ObjClassCollection([class_pedestrian, class_road])

с_3 = c_1.merge(c_2)
print(с_3.to_json())
# Output: [
#     {
#         "title":"pedestrian",
#         "shape":"rectangle",
#         "color":"#8A0F27",
#         "geometry_config":{},
#         "hotkey":""
#     },
#     {
#         "title":"road",
#         "shape":"rectangle",
#         "color":"#8A620F",
#         "geometry_config":{},
#         "hotkey":""
#     },
#     {
#         "title":"car",
#         "shape":"rectangle",
#         "color":"#8A0F3B",
#         "geometry_config":{},
#         "hotkey":""
#     },
#     {
#         "title":"bicycle",
#         "shape":"rectangle",
#         "color":"#0F8A1F",
#         "geometry_config":{},
#         "hotkey":""
#     }
# ]

# Merge will raise ValueError if item name from given list is in collection but items in both are different
class_bicycle_1 = sly.ObjClass('bicycle', sly.Rectangle)
class_bicycle_2 = sly.ObjClass('bicycle', sly.Bitmap)

classes_1 = sly.ObjClassCollection([class_bicycle_1])
classes_2 = sly.ObjClassCollection([class_bicycle_2])

test_merge = classes_1.merge(classes_2)
# Output: ValueError: Error during merge for key 'bicycle': values are different

# Let's try to create now a collection where ObjClasses have identical names
class_cow = sly.ObjClass('cow', sly.Rectangle)
class_chicken = sly.ObjClass('cow', sly.Rectangle)

test_classes = sly.ObjClassCollection([class_cow, class_chicken])
# Output: DuplicateKeyError: "Key 'cow' already exists"

item_type

alias of supervisely_lib.annotation.obj_class.ObjClass

to_json() → List[dict]

Convert the ObjClassCollection to a list of json dicts. Read more about Supervisely format.

Returns

List of dicts in json format

Return type

List[dict]

Usage example

class_lemon = sly.ObjClass('lemon', sly.Rectangle)
class_kiwi = sly.ObjClass('kiwi', sly.Bitmap)

# Add ObjClasses to ObjClassCollection
classes = sly.ObjClassCollection([class_lemon, class_kiwi])

classes_json = classes.to_json()
print(classes_json)
# Output: [
#      {
#           "title": "lemon",
#           "shape": "rectangle",
#           "color": "#300F8A",
#           "geometry_config": {},
#           "hotkey": ""
#      },
#      {
#           "title": "kiwi",
#           "shape": "bitmap",
#           "color": "#7C0F8A",
#           "geometry_config": {},
#           "hotkey": ""
#      }
# ]

classmethod from_json(data: List[dict]) → supervisely_lib.annotation.obj_class_collection.ObjClassCollection

Convert a list with dicts in json format to ObjClassCollection. Read more about Supervisely format.

Parameters

data (List[dict]) – List with dicts in json format.

Returns

ObjClassCollection object

Return type

ObjClassCollection

Usage example

data = [
     {
          "title": "lemon",
          "shape": "rectangle",
          "color": "#300F8A",
          "hotkey": ""
     },
     {
          "title": "kiwi",
          "shape": "bitmap",
          "color": "#7C0F8A",
          "hotkey": ""
     }
]

classes = sly.ObjClassCollection.from_json(data)

validate_classes_colors(logger: logger = None) → str or None

Checks for unique colors in the ObjClassCollection.

Parameters

logger (logger, optional) – Input logger.

Returns

Notification if there are objects with the same colors, otherwise None

Return type

str or NoneType

Usage example

# Let's create 2 ObjClasses with the same color
class_lemon = sly.ObjClass('lemon', sly.Rectangle, [0, 0, 0])
class_kiwi = sly.ObjClass('kiwi', sly.Bitmap, [0, 0, 0])

# Add them to ObjClassCollection
classes = sly.ObjClassCollection([class_lemon, class_kiwi])

print(classes.validate_classes_colors())
# Output: Classes ['lemon', 'kiwi'] have the same RGB color = [0, 0, 0]

# Now let's change colors of our ObjClasses
class_lemon = sly.ObjClass('lemon', sly.Rectangle, [255, 0, 0])
class_kiwi = sly.ObjClass('kiwi', sly.Bitmap, [0, 0, 255])

classes = sly.ObjClassCollection([class_lemon, class_kiwi])

print(classes.validate_classes_colors())
# Output: None