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1# Copyright 2014 The Android Open Source Project
2#
3# Licensed under the Apache License, Version 2.0 (the "License");
4# you may not use this file except in compliance with the License.
5# You may obtain a copy of the License at
6#
7#      http://www.apache.org/licenses/LICENSE-2.0
8#
9# Unless required by applicable law or agreed to in writing, software
10# distributed under the License is distributed on an "AS IS" BASIS,
11# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12# See the License for the specific language governing permissions and
13# limitations under the License.
14
15import its.image
16import its.device
17import its.caps
18import its.objects
19import os.path
20import pylab
21import matplotlib
22import matplotlib.pyplot
23import numpy
24
25#AE must converge within this number of auto requests for EV
26THREASH_CONVERGE_FOR_EV = 8
27
28def main():
29    """Tests that EV compensation is applied.
30    """
31    LOCKED = 3
32
33    NAME = os.path.basename(__file__).split(".")[0]
34
35    MAX_LUMA_DELTA_THRESH = 0.05
36
37    with its.device.ItsSession() as cam:
38        props = cam.get_camera_properties()
39        its.caps.skip_unless(its.caps.manual_sensor(props) and
40                             its.caps.manual_post_proc(props) and
41                             its.caps.per_frame_control(props) and
42                             its.caps.ev_compensation(props))
43
44        debug = its.caps.debug_mode()
45        if debug:
46            fmt = its.objects.get_largest_yuv_format(props)
47        else:
48            fmt = its.objects.get_smallest_yuv_format(props)
49
50        ev_compensation_range = props['android.control.aeCompensationRange']
51        range_min = ev_compensation_range[0]
52        range_max = ev_compensation_range[1]
53        ev_per_step = its.objects.rational_to_float(
54                props['android.control.aeCompensationStep'])
55        steps_per_ev = int(round(1.0 / ev_per_step))
56        ev_steps = range(range_min, range_max + 1, steps_per_ev)
57        imid = len(ev_steps) / 2
58        ev_shifts = [pow(2, step * ev_per_step) for step in ev_steps]
59        lumas = []
60
61        # Converge 3A, and lock AE once converged. skip AF trigger as
62        # dark/bright scene could make AF convergence fail and this test
63        # doesn't care the image sharpness.
64        cam.do_3a(ev_comp=0, lock_ae=True, do_af=False)
65
66        for ev in ev_steps:
67
68            # Capture a single shot with the same EV comp and locked AE.
69            req = its.objects.auto_capture_request()
70            req['android.control.aeExposureCompensation'] = ev
71            req["android.control.aeLock"] = True
72            # Use linear tone curve to avoid brightness being impacted
73            # by tone curves.
74            req["android.tonemap.mode"] = 0
75            req["android.tonemap.curveRed"] = [0.0,0.0, 1.0,1.0]
76            req["android.tonemap.curveGreen"] = [0.0,0.0, 1.0,1.0]
77            req["android.tonemap.curveBlue"] = [0.0,0.0, 1.0,1.0]
78            caps = cam.do_capture([req]*THREASH_CONVERGE_FOR_EV, fmt)
79
80            for cap in caps:
81                if (cap['metadata']['android.control.aeState'] == LOCKED):
82                    y = its.image.convert_capture_to_planes(cap)[0]
83                    tile = its.image.get_image_patch(y, 0.45,0.45,0.1,0.1)
84                    lumas.append(its.image.compute_image_means(tile)[0])
85                    break
86            assert(cap['metadata']['android.control.aeState'] == LOCKED)
87
88        print "ev_step_size_in_stops", ev_per_step
89        shift_mid = ev_shifts[imid]
90        luma_normal = lumas[imid] / shift_mid
91        expected_lumas = [min(1.0, luma_normal * ev_shift) for ev_shift in ev_shifts]
92
93        pylab.plot(ev_steps, lumas, 'r')
94        pylab.plot(ev_steps, expected_lumas, 'b')
95        matplotlib.pyplot.savefig("%s_plot_means.png" % (NAME))
96
97        luma_diffs = [expected_lumas[i] - lumas[i] for i in range(len(ev_steps))]
98        max_diff = max(abs(i) for i in luma_diffs)
99        avg_diff = abs(numpy.array(luma_diffs)).mean()
100        print "Max delta between modeled and measured lumas:", max_diff
101        print "Avg delta between modeled and measured lumas:", avg_diff
102        assert(max_diff < MAX_LUMA_DELTA_THRESH)
103
104if __name__ == '__main__':
105    main()
106