File size: 9,467 Bytes
8f76218
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
"""The VideoStreamInterface provides an easy way to apply transforms to a video stream"""
import base64
import io
import time

import numpy as np
import panel as pn
import param
import PIL
from PIL import Image

HEIGHT = 400
WIDTH = 400
TIMEOUT = 250
ACCENT = "#fef3c7"


def to_instance(value, **params):
    """Converts the value to an instance
    Args:
        value: A param.Parameterized class or instance
    Returns:
        An instance of the param.Parameterized class
    """
    if isinstance(value, param.Parameterized):
        value.param.update(**params)
        return value
    return value(**params)


class Timer(pn.viewable.Viewer):
    """Helper Component used to show duration trends"""

    _trends = param.Dict()

    def __init__(self, **params):
        super().__init__()

        self.last_updates = {}
        self._trends = {}

        self._layout = pn.Row(**params)

    def time_it(self, name, func, *args, **kwargs):
        """Measures the duration of the execution of the func function and reports it under the
        name specified"""
        start = time.time()
        result = func(*args, **kwargs)
        end = time.time()
        duration = round(end - start, 2)
        self._report(name=name, duration=duration)
        return result

    def inc_it(self, name):
        """Measures the duration since the last time `inc_it` was called and reports it under the
        specified name"""
        start = self.last_updates.get(name, time.time())
        end = time.time()
        duration = round(end - start, 2)
        self._report(name=name, duration=duration)
        self.last_updates[name] = end

    def _report(self, name, duration):
        if not name in self._trends:
            self._trends[name] = pn.indicators.Trend(
                title=name,
                data={"x": [1], "y": [duration]},
                plot_color=ACCENT,
                height=100,
                width=150,
                sizing_mode="fixed",
            )
            self.param.trigger("_trends")
        else:
            trend = self._trends[name]
            next_x = max(trend.data["x"]) + 1
            trend.stream({"x": [next_x], "y": [duration]}, rollover=10)

    @pn.depends("_trends")
    def _panel(self):
        self._layout[:] = list(self._trends.values())
        return self._layout

    def __panel__(self):
        return self._panel


class ImageTransform(pn.viewable.Viewer):
    """Base class for image transforms."""

    def __init__(self, **params):
        super().__init__(**params)

        with param.edit_constant(self):
            self.name = self.__class__.name.replace("Transform", "")
        self.view = self.create_view()

    def __panel__(self):
        return self.view

    def run(self, image: str, height: int = HEIGHT, width: int = WIDTH) -> str:
        """Transforms the base64 encoded jpg image to a base64 encoded jpg BytesIO object"""
        raise NotImplementedError()

    def create_view(self):
        """Creates a view of the parameters of the transform to enable the user to configure them"""
        return pn.Param(self, name=self.name)

    def transform(self, image):
        """Transforms the image"""
        raise NotImplementedError()


class PILImageTransform(ImageTransform):
    """Base class for PIL image transforms"""

    @staticmethod
    def to_pil_img(value: str, height=HEIGHT, width=WIDTH):
        """Converts a base64 jpeg image string to a PIL.Image"""
        encoded_data = value.split(",")[1]
        base64_decoded = base64.b64decode(encoded_data)
        image = Image.open(io.BytesIO(base64_decoded))
        image.draft("RGB", (height, width))
        return image

    @staticmethod
    def from_pil_img(image: Image):
        """Converts a PIL.Image to a base64 encoded JPG BytesIO object"""
        buff = io.BytesIO()
        image.save(buff, format="JPEG")
        return buff

    def run(self, image: str, height: int = HEIGHT, width: int = WIDTH) -> io.BytesIO:
        pil_img = self.to_pil_img(image, height=height, width=width)

        transformed_image = self.transform(pil_img)

        return self.from_pil_img(transformed_image)

    def transform(self, image: PIL.Image) -> PIL.Image:
        """Transforms the PIL.Image image"""
        raise NotImplementedError()


class NumpyImageTransform(ImageTransform):
    """Base class for np.ndarray image transforms"""

    @staticmethod
    def to_np_ndarray(image: str, height=HEIGHT, width=WIDTH) -> np.ndarray:
        """Converts a base64 encoded jpeg string to a np.ndarray"""
        pil_img = PILImageTransform.to_pil_img(image, height=height, width=width)
        return np.array(pil_img)

    @staticmethod
    def from_np_ndarray(image: np.ndarray) -> io.BytesIO:
        """Converts np.ndarray jpeg image to a jpeg BytesIO instance"""
        if image.dtype == np.dtype("float64"):
            image = (image * 255).astype(np.uint8)
        pil_img = PIL.Image.fromarray(image)
        return PILImageTransform.from_pil_img(pil_img)

    def run(self, image: str, height: int = HEIGHT, width: int = WIDTH) -> io.BytesIO:
        np_array = self.to_np_ndarray(image, height=height, width=width)

        transformed_image = self.transform(np_array)

        return self.from_np_ndarray(transformed_image)

    def transform(self, image: np.ndarray) -> np.ndarray:
        """Transforms the nd.array image"""
        raise NotImplementedError()


class VideoStreamInterface(pn.viewable.Viewer):
    """An easy to use interface for a VideoStream and a set of transforms"""

    video_stream = param.ClassSelector(
        class_=pn.widgets.VideoStream, constant=True, doc="The source VideoStream"
    )

    height = param.Integer(
        HEIGHT,
        bounds=(10, 2000),
        step=10,
        doc="""The height of the image converted and shown""",
    )
    width = param.Integer(
        WIDTH,
        bounds=(10, 2000),
        step=10,
        doc="""The width of the image converted and shown""",
    )

    transform = param.Selector(doc="The currently selected transform")

    def __init__(
        self,
        transforms,
        timeout=TIMEOUT,
        paused=False,
        **params,
    ):
        super().__init__(
            video_stream=pn.widgets.VideoStream(
                name="Video Stream",
                timeout=timeout,
                paused=paused,
                height=0,
                width=0,
                visible=False,
                format="jpeg",
            ),
            **params,
        )
        self.image = pn.pane.JPG(
            height=self.height, width=self.width, sizing_mode="fixed"
        )
        self._updating = False
        transforms = [to_instance(transform) for transform in transforms]
        self.param.transform.objects = transforms
        self.transform = transforms[0]
        self.timer = Timer(sizing_mode="stretch_width")
        self.settings = self._create_settings()
        self._panel = self._create_panel()

    def _create_settings(self):
        return pn.Column(
            pn.Param(
                self.video_stream,
                parameters=["timeout", "paused"],
                widgets={
                    "timeout": {
                        "widget_type": pn.widgets.IntSlider,
                        "start": 10,
                        "end": 2000,
                        "step": 10,
                    }
                },
            ),
            self.timer,
            pn.Param(self, parameters=["height", "width"], name="Image"),
            pn.Param(
                self,
                parameters=["transform"],
                expand_button=False,
                expand=False,
                widgets={
                    "transform": {
                        "widget_type": pn.widgets.RadioButtonGroup,
                        "orientation": "vertical",
                        "button_type": "success",
                    }
                },
                name="Transform",
            ),
            self._get_transform,
        )

    def _create_panel(self):
        return pn.Row(
            self.video_stream,
            pn.layout.HSpacer(),
            self.image,
            pn.layout.HSpacer(),
            sizing_mode="stretch_width",
            align="center",
        )

    @pn.depends("height", "width", watch=True)
    def _update_height_width(self):
        self.image.height = self.height
        self.image.width = self.width

    @pn.depends("transform")
    def _get_transform(self):
        # Hack: returning self.transform stops working after browsing the transforms for a while
        return self.transform.view

    def __panel__(self):
        return self._panel

    @pn.depends("video_stream.value", watch=True)
    def _handle_stream(self):
        if self._updating:
            return

        self._updating = True
        if self.transform and self.video_stream.value:
            value = self.video_stream.value
            try:
                image = self.timer.time_it(
                    name="Transform",
                    func=self.transform.run,
                    image=value,
                    height=self.height,
                    width=self.width,
                )
                self.image.object = image
            except PIL.UnidentifiedImageError:
                print("unidentified image")

            self.timer.inc_it("last update")
        self._updating = False