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 16 Android Camera Imaging Test Suite (ITS) 17 ======================================= 18 19 1. Introduction 20 --------------- 21 22 The ITS is a framework for running tests on the images produced by an Android 23 camera. The general goal of each test is to configure the camera in a desired 24 manner and capture one or more shots, and then examine the shots to see if 25 they contain the expected image data. Many of the tests will require that the 26 camera is pointed at a specific target chart or be illuminated at a specific 27 intensity. 28 29 2. Setup 30 -------- 31 32 There are two components to the ITS: 33 1. The Android device running ItsService.apk. 34 2. A host machine connected to the Android device that runs Python tests. 35 36 2.1. Device setup 37 ----------------- 38 39 Build and install ItsService.apk for your device. After setting up your 40 shell for Android builds, from the pdk/apps/CameraITS directory run the 41 following commands: 42 43 cd service 44 mm 45 adb install -r <YOUR_OUTPUT_PATH>/ItsService.apk 46 47 using whatever path is appropriate to your output ItsService.apk file. 48 49 2.2. Host PC setup 50 ------------------ 51 52 The first pre-requisite is the Android SDK, as adb is used to communicate with 53 the device. 54 55 The test framework is based on Python on the host machine. It requires 56 Python 2.7 and the scipy/numpy stack, including the Python Imaging Library. 57 58 (For Ubuntu users) 59 60 sudo apt-get install python-numpy python-scipy python-matplotlib 61 62 (For other users) 63 64 All of these pieces can be installed on your host machine separately, 65 however it is highly recommended to install a bundled distribution of 66 Python that comes with these modules. Some different bundles are listed 67 here: 68 69 http://www.scipy.org/install.html 70 71 Of these, Anaconda has been verified to work with these scripts, and it is 72 available on Mac, Linux, and Windows from here: 73 74 http://continuum.io/downloads 75 76 Note that the Anaconda python executable's directory must be at the front of 77 your PATH environment variable, assuming that you are using this Python 78 distribution. The Anaconda installer may set this up for you automatically. 79 80 Once your Python installation is ready, set up the test environment. 81 82 2.2.1. Linux + Mac OS X 83 ----------------------- 84 85 On Linux or Mac OS X, run the following command (in a terminal) from the 86 pdk/apps/CameraITS directory, from a bash shell: 87 88 source build/envsetup.sh 89 90 This will do some basic sanity checks on your Python installation, and set up 91 the PYTHONPATH environment variable. 92 93 2.2.2. Windows 94 -------------- 95 96 On Windows, the bash script won't run (unless you have cygwin (which has not 97 been tested)), but all you need to do is set your PYTHONPATH environment 98 variable in your shell to point to the pdk/apps/CameraITS/pymodules directory, 99 giving an absolute path. Without this, you'll get "import" errors when running 100 the test scripts. 101 102 3. Python framework overview 103 ---------------------------- 104 105 The Python modules are under the pymodules directory, in the "its" package. 106 107 * its.device: encapsulates communication with ItsService.apk service running 108 on the device 109 * its.objects: contains a collection of functions for creating Python objects 110 corresponding to the Java objects which ItsService.apk uses 111 * its.image: contains a collection of functions (built on numpy arrays) for 112 processing captured images 113 * its.error: the exception/error class used in this framework 114 115 All of these module have associated unit tests; to run the unit tests, execute 116 the modules (rather than importing them). 117 118 3.1. Device control 119 ------------------- 120 121 The its.device.ItsSession class encapsulates a session with a connected device 122 under test (which is running ItsService.apk). 123 124 As an overview, the ItsSession.do_capture() function takes a Python dictionary 125 object as an argument, converts that object to JSON, and sends it to the 126 device over adb which then deserializes from the JSON object representation to 127 Camera2 Java objects (CaptureRequests) which are used to specify one or more 128 captures. Once the captures are complete, the resultant images are copied back 129 to the host machine (using adb pull), along with JSON representations of the 130 CaptureResult and other objects that describe the shot that was actually taken. 131 132 The Python dictionary object that is used to specify what shots to capture and 133 that is passed as an argument to the do_capture() function can have the 134 following top-level keys: 135 136 captureRequest 137 captureRequestList 138 outputSurface 139 140 Exactly one of captureRequest and captureRequestList must be present, and 141 outputSurface is optional. Look at the tests directory for examples of 142 specifying these objects. 143 144 The captureRequest object can contain key/value entries corresponding to any 145 of the Java CaptureRequest object fields. The captureRequestList object is 146 a list of such objecs, corresponding to a burst capture specification. 147 148 The outputSurface object is used to specify the width, height, and format of 149 the output images that are captured. Currently supported formats are "jpg" and 150 "yuv", where "yuv" is YUV420 fully planar. The default output surface is a 151 full sensor YUV420 frame. 152 153 The metadata that is returned along with the captured images is also in JSON 154 format, serialized from the CaptureRequest and CaptureResult objects that were 155 passed to the capture listener, as well as the CameraProperties object. 156 157 3.2. Image processing and analysis 158 ---------------------------------- 159 160 The its.image module is a collection of Python functions, built on top of numpy 161 arrays, for manipulating captured images. Some functions of note include: 162 163 load_yuv420_to_rgb_image 164 apply_lut_to_image 165 apply_matrix_to_image 166 write_image 167 168 The scripts in the tests directory make use of these modules. 169 170 Note that it's important to do heavy image processing using the efficient numpy 171 ndarray operations, rather than writing complex loops in standard Python to 172 process pixels. Refer to online docs and examples of numpy for information on 173 this. 174 175 3.3. Tests 176 ---------- 177 178 The tests directory contains a number of self-contained test scripts. All 179 tests should pass if the tree is in a good state. 180 181 Most of the tests save various files in the current directory. To have all the 182 output files put into a separate directory, run the script from that directory, 183 for example: 184 185 mkdir out 186 cd out 187 python ../tests/test_linearity.py 188 189 Any test can be specified to reboot the camera prior to capturing any shots, by 190 adding a "reboot" or "reboot=N" command line argument, where N is the number of 191 seconds to wait after rebooting the device before sending any commands; the 192 default is 30 seconds. 193 194 python tests/test_linearity.py reboot 195 python tests/test_linearity.py reboot=20 196 197 3.4. Docs 198 --------- 199 200 The pydoc tool can generate HTML docs for the ITS Python modules, using the 201 following command (run after PYTHONPATH has been set up as described above): 202 203 pydoc -w its its.device its.image its.error its.objects 204 205 4. Known issues 206 --------------- 207 208 The Python test scripts don't work if multiple devices are connected to the 209 host machine; currently, the its.device module uses a simplistic "adb -d" 210 approach to communicating with the device, assuming that there is only one 211 device connected. Fixing this is a TODO. 212 213
