Seven segments OCR image processing (#7632)

* Add initial seven segments OCR image processing

* Fix typo

.coveragerc

@@ -252,6 +252,7 @@ omit =
     homeassistant/components/ifttt.py
     homeassistant/components/image_processing/dlib_face_detect.py
     homeassistant/components/image_processing/dlib_face_identify.py
+    homeassistant/components/image_processing/seven_segments.py
     homeassistant/components/joaoapps_join.py
     homeassistant/components/keyboard.py
     homeassistant/components/keyboard_remote.py

homeassistant/components/image_processing/__init__.py

@@ -11,25 +11,26 @@ import os
 
 import voluptuous as vol
 
+import homeassistant.helpers.config_validation as cv
 from homeassistant.config import load_yaml_config_file
 from homeassistant.const import (
     ATTR_ENTITY_ID, CONF_NAME, CONF_ENTITY_ID)
 from homeassistant.exceptions import HomeAssistantError
-import homeassistant.helpers.config_validation as cv
 from homeassistant.helpers.entity import Entity
 from homeassistant.helpers.entity_component import EntityComponent
 from homeassistant.loader import get_component
 
+_LOGGER = logging.getLogger(__name__)
+
 DOMAIN = 'image_processing'
 DEPENDENCIES = ['camera']
 
-_LOGGER = logging.getLogger(__name__)
-
 SCAN_INTERVAL = timedelta(seconds=10)
 
 DEVICE_CLASSES = [
-    'alpr',        # automatic license plate recognition
-    'face',        # face
+    'alpr',        # Automatic license plate recognition
+    'face',        # Face
+    'ocr',         # OCR
 ]
 
 SERVICE_SCAN = 'scan'

homeassistant/components/image_processing/seven_segments.py

@@ -0,0 +1,114 @@
+"""
+Local optical character recognition processing of seven segements displays.
+
+For more details about this platform, please refer to the documentation at
+https://home-assistant.io/components/image_processing.seven_segments/
+"""
+import asyncio
+import logging
+import io
+import os
+
+import voluptuous as vol
+
+import homeassistant.helpers.config_validation as cv
+from homeassistant.core import split_entity_id
+from homeassistant.components.image_processing import (
+    PLATFORM_SCHEMA, ImageProcessingEntity, CONF_SOURCE, CONF_ENTITY_ID,
+    CONF_NAME)
+
+_LOGGER = logging.getLogger(__name__)
+
+CONF_DIGITS = 'digits'
+CONF_HEIGHT = 'height'
+CONF_SSOCR_BIN = 'ssocr'
+CONF_THRESHOLD = 'threshold'
+CONF_WIDTH = 'width'
+CONF_X_POS = 'x_position'
+CONF_Y_POS = 'y_position'
+
+DEFAULT_BINARY = 'ssocr'
+
+PLATFORM_SCHEMA = PLATFORM_SCHEMA.extend({
+    vol.Optional(CONF_DIGITS, default=-1): cv.positive_int,
+    vol.Optional(CONF_HEIGHT, default=0): cv.positive_int,
+    vol.Optional(CONF_SSOCR_BIN, default=DEFAULT_BINARY): cv.string,
+    vol.Optional(CONF_THRESHOLD, default=0): cv.positive_int,
+    vol.Optional(CONF_WIDTH, default=0): cv.positive_int,
+    vol.Optional(CONF_X_POS, default=0): cv.string,
+    vol.Optional(CONF_Y_POS, default=0): cv.positive_int,
+})
+
+
+@asyncio.coroutine
+def async_setup_platform(hass, config, async_add_devices, discovery_info=None):
+    """Set up the Seven segments OCR platform."""
+    entities = []
+    for camera in config[CONF_SOURCE]:
+        entities.append(ImageProcessingSsocr(
+            hass, camera[CONF_ENTITY_ID], config, camera.get(CONF_NAME)
+        ))
+
+    async_add_devices(entities)
+
+
+class ImageProcessingSsocr(ImageProcessingEntity):
+    """Representation of the seven segments OCR image processing entity."""
+
+    def __init__(self, hass, camera_entity, config, name):
+        """Initialize seven segments processing."""
+        self.hass = hass
+        self._camera_entity = camera_entity
+        if name:
+            self._name = name
+        else:
+            self._name = "SevenSegement OCR {0}".format(
+                split_entity_id(camera_entity)[1])
+        self._state = None
+        self.filepath = os.path.join(self.hass.config.config_dir, 'ocr.png')
+        self._command = [
+            config[CONF_SSOCR_BIN], 'erosion', 'make_mono', 'crop',
+            str(config[CONF_X_POS]), str(config[CONF_Y_POS]),
+            str(config[CONF_WIDTH]), str(config[CONF_HEIGHT]), '-t',
+            str(config[CONF_THRESHOLD]), '-d', str(config[CONF_DIGITS]),
+            self.filepath
+        ]
+
+    @property
+    def device_class(self):
+        """Return the class of this device, from component DEVICE_CLASSES."""
+        return 'ocr'
+
+    @property
+    def camera_entity(self):
+        """Return camera entity id from process pictures."""
+        return self._camera_entity
+
+    @property
+    def name(self):
+        """Return the name of the image processor."""
+        return self._name
+
+    @property
+    def state(self):
+        """Return the state of the entity."""
+        return self._state
+
+    def process_image(self, image):
+        """Process the image."""
+        from PIL import Image
+        import subprocess
+
+        stream = io.BytesIO(image)
+        img = Image.open(stream)
+        img.save(self.filepath, 'png')
+
+        ocr = subprocess.Popen(
+            self._command, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
+        out = ocr.communicate()
+        if out[0] != b'':
+            self._state = out[0].strip().decode('utf-8')
+        else:
+            self._state = None
+            _LOGGER.warning(
+                "Unable to detect value: %s", out[1].strip().decode('utf-8'))