1 # Copyright 2013 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 15 import its.image 16 import its.device 17 import its.objects 18 import pylab 19 import os.path 20 import matplotlib 21 import matplotlib.pyplot 22 import numpy 23 24 def main(): 25 """Test that when the black level is locked, it doesn't change. 26 27 Shoot with the camera covered (i.e.) dark/black. The test varies the 28 sensitivity parameter and checks if the black level changes. 29 """ 30 NAME = os.path.basename(__file__).split(".")[0] 31 32 NUM_STEPS = 5 33 34 req = { 35 "android.blackLevel.lock": True, 36 "android.control.mode": 0, 37 "android.control.aeMode": 0, 38 "android.control.awbMode": 0, 39 "android.control.afMode": 0, 40 "android.sensor.frameDuration": 0, 41 "android.sensor.exposureTime": 10*1000*1000 42 } 43 44 # The most frequent pixel value in each image; assume this is the black 45 # level, since the images are all dark (shot with the lens covered). 46 modes = [] 47 48 with its.device.ItsSession() as cam: 49 props = cam.get_camera_properties() 50 sens_range = props['android.sensor.info.sensitivityRange'] 51 sensitivities = range(sens_range[0], 52 sens_range[1]+1, 53 int((sens_range[1] - sens_range[0]) / NUM_STEPS)) 54 for si, s in enumerate(sensitivities): 55 req["android.sensor.sensitivity"] = s 56 cap = cam.do_capture(req) 57 yimg,_,_ = its.image.convert_capture_to_planes(cap) 58 hist,_ = numpy.histogram(yimg*255, 256, (0,256)) 59 modes.append(numpy.argmax(hist)) 60 61 # Add this histogram to a plot; solid for shots without BL 62 # lock, dashes for shots with BL lock 63 pylab.plot(range(16), hist.tolist()[:16]) 64 65 pylab.xlabel("Luma DN, showing [0:16] out of full [0:256] range") 66 pylab.ylabel("Pixel count") 67 pylab.title("Histograms for different sensitivities") 68 matplotlib.pyplot.savefig("%s_plot_histograms.png" % (NAME)) 69 70 # Check that the black levels are all the same. 71 print "Black levels:", modes 72 assert(all([modes[i] == modes[0] for i in range(len(modes))])) 73 74 if __name__ == '__main__': 75 main() 76 77
