1 /*
2 * Copyright (C) 2013 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 // Native function to extract exposure from image (handed down as ByteBuffer).
18
19 #include "exposure.h"
20
21 #include <math.h>
22 #include <string.h>
23 #include <jni.h>
24 #include <unistd.h>
25 #include <android/log.h>
26
27
28 jfloat
Java_androidx_media_filterfw_samples_simplecamera_ExposureFilter_overExposureOperator(JNIEnv * env,jclass clazz,jint width,jint height,jobject imageBuffer)29 Java_androidx_media_filterfw_samples_simplecamera_ExposureFilter_overExposureOperator(
30 JNIEnv* env, jclass clazz, jint width, jint height, jobject imageBuffer) {
31 if (imageBuffer == 0) {
32 return 0.0f;
33 }
34 const int numPixels = width * height;
35 unsigned char* srcPtr = static_cast<unsigned char*>(env->GetDirectBufferAddress(imageBuffer));
36 int output = 0;
37 float tempLuminance = 0.0f;
38
39 for (int i = 0; i < numPixels; i++) {
40 tempLuminance = (0.2126f * *(srcPtr + 4 * i) +
41 0.7152f * *(srcPtr + 4 * i + 1) +
42 0.0722f * *(srcPtr + 4 * i + 2));
43 if (tempLuminance + 5 >= 255) {
44 output++;
45 }
46 }
47 return (static_cast<float>(output)) / numPixels;
48 }
49
50 jfloat
Java_androidx_media_filterfw_samples_simplecamera_ExposureFilter_underExposureOperator(JNIEnv * env,jclass clazz,jint width,jint height,jobject imageBuffer)51 Java_androidx_media_filterfw_samples_simplecamera_ExposureFilter_underExposureOperator(
52 JNIEnv* env, jclass clazz, jint width, jint height, jobject imageBuffer) {
53 if (imageBuffer == 0) {
54 return 0.0f;
55 }
56 const int numPixels = width * height;
57 unsigned char* srcPtr = static_cast<unsigned char*>(env->GetDirectBufferAddress(imageBuffer));
58 int output = 0;
59 float tempLuminance = 0.0f;
60
61 for (int i = 0; i < numPixels; i++) {
62 tempLuminance = (0.2126f * *(srcPtr + 4 * i) +
63 0.7152f * *(srcPtr + 4 * i + 1) +
64 0.0722f * *(srcPtr + 4 * i + 2));
65 if (tempLuminance - 5 <= 0) {
66 output++;
67 }
68 }
69 return (static_cast<float>(output)) / numPixels;
70 }
71