1 /*
2  * Copyright (C) 2015 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #define LOG_TAG "ITS-StatsImage-JNI"
18 // #define LOG_NDEBUG 0
19 #include <android/log.h>
20 #include <utils/Log.h>
21 
22 #include <jni.h>
23 #include <stdio.h>
24 #include <sys/types.h>
25 #include <sys/stat.h>
26 #include <inttypes.h>
27 #include <string.h>
28 
com_android_cts_verifier_camera_its_computeStatsImage(JNIEnv * env,jobject thiz,jbyteArray img,jint width,jint height,jint aax,jint aay,jint aaw,jint aah,jint gridWidth,jint gridHeight)29 jfloatArray com_android_cts_verifier_camera_its_computeStatsImage(JNIEnv* env, jobject thiz,
30         // The full pixel array read off the sensor.
31         jbyteArray img,
32         jint width, jint height,
33         // The active array crop region.
34         jint aax, jint aay, jint aaw, jint aah,
35         // The size of each grid cell to use when computing stats from the active array.
36         jint gridWidth, jint gridHeight)
37 {
38     int bufSize = (int)(env->GetArrayLength(img));
39     unsigned char *buf = (unsigned char*)env->GetByteArrayElements(img, /*is_copy*/NULL);
40 
41     // Size of the full raw image pixel array.
42     const int paw = width;
43     const int pah = height;
44     // Size of each grid cell.
45     const int gw = gridWidth;
46     const int gh = gridHeight;
47     // Number of grid cells (rounding down to full cells only at right+bottom edges).
48     const int ngx = aaw / gw;
49     const int ngy = aah / gh;
50 
51     float *mean = new float[ngy*ngx*4];
52     float *var = new float[ngy*ngx*4];
53     // For each grid cell ...
54     for (int gy = 0; gy < ngy; gy++) {
55         for (int gx = 0; gx < ngx; gx++) {
56             float sum[4] = {0};
57             float sumSq[4] = {0};
58             int count[4] = {0};
59             // Iterate over pixels in the grid cell
60             for (int y = aay+gy*gh; y < aay+(gy+1)*gh; y++) {
61                 int chnOffset = (y & 0x1) * 2;
62                 unsigned char *pbuf = buf + 2*y*paw + 2*gx*gw + 2*aax;
63                 for (int x = aax+gx*gw; x < aax+(gx+1)*gw; x++) {
64                     // input is RAW16
65                     int byte0 = *pbuf++;
66                     int byte1 = *pbuf++;
67                     int pixelValue = (byte1 << 8) | byte0;
68                     int ch = chnOffset + (x & 1);
69                     sum[ch] += pixelValue;
70                     sumSq[ch] += pixelValue * pixelValue;
71                     count[ch] += 1;
72                 }
73             }
74             for (int ch = 0; ch < 4; ch++) {
75                 float m = (float)sum[ch] / count[ch];
76                 float mSq = (float)sumSq[ch] / count[ch];
77                 mean[gy*ngx*4 + gx*4 + ch] = m;
78                 var[gy*ngx*4 + gx*4 + ch] = mSq - m*m;
79             }
80         }
81     }
82 
83     jfloatArray ret = env->NewFloatArray(ngx*ngy*4*2);
84     env->SetFloatArrayRegion(ret, 0, ngx*ngy*4, (float*)mean);
85     env->SetFloatArrayRegion(ret, ngx*ngy*4, ngx*ngy*4, (float*)var);
86     delete [] mean;
87     delete [] var;
88     return ret;
89 }
90 
91 static JNINativeMethod gMethods[] = {
92     {  "computeStatsImage", "([BIIIIIIII)[F",
93             (void *) com_android_cts_verifier_camera_its_computeStatsImage  },
94 };
95 
register_com_android_cts_verifier_camera_its_StatsImage(JNIEnv * env)96 int register_com_android_cts_verifier_camera_its_StatsImage(JNIEnv* env)
97 {
98     jclass clazz = env->FindClass("com/android/cts/verifier/camera/its/StatsImage");
99 
100     return env->RegisterNatives(clazz, gMethods,
101             sizeof(gMethods) / sizeof(JNINativeMethod));
102 }
103