1 files changed, 128 insertions, 0 deletions
diff --git a/tests/Camera2Tests/SmartCamera/SimpleCamera/jni/histogram.cpp b/tests/Camera2Tests/SmartCamera/SimpleCamera/jni/histogram.cpp
new file mode 100644
index 0000000..ba060d4
--- /dev/null
+++ b/tests/Camera2Tests/SmartCamera/SimpleCamera/jni/histogram.cpp
@@ -0,0 +1,128 @@
+/*
+ * Copyright (C) 2012 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+// Native function to extract histogram from image (handed down as ByteBuffer).
+
+#include "histogram.h"
+
+#include <string.h>
+#include <jni.h>
+#include <unistd.h>
+#include <android/log.h>
+
+#include "imgprocutil.h"
+
+inline void addPixelToHistogram(unsigned char*& pImg, int* pHist, int numBins) {
+    int R = *(pImg++);
+    int G = *(pImg++);
+    int B = *(pImg++);
+    ++pImg;
+    int i = getIntensityFast(R, G, B);
+    int bin = clamp(0, static_cast<int>(static_cast<float>(i * numBins) / 255.0f), numBins - 1);
+    ++pHist[bin];
+}
+
+void Java_androidx_media_filterpacks_histogram_GrayHistogramFilter_extractHistogram(
+    JNIEnv* env, jclass clazz, jobject imageBuffer, jobject maskBuffer, jobject histogramBuffer )
+{
+    unsigned char* pImg = static_cast<unsigned char*>(env->GetDirectBufferAddress(imageBuffer));
+    int* pHist = static_cast<int*>(env->GetDirectBufferAddress(histogramBuffer));
+    int numPixels  = env->GetDirectBufferCapacity(imageBuffer) / 4;  // 4 bytes per pixel
+    int numBins    = env->GetDirectBufferCapacity(histogramBuffer);
+
+    unsigned char* pMask = NULL;
+    if(maskBuffer != NULL) {
+        pMask = static_cast<unsigned char*>(env->GetDirectBufferAddress(maskBuffer));
+    }
+
+    for(int i = 0; i < numBins; ++i) pHist[i] = 0;
+
+    if(pMask == NULL) {
+        for( ; numPixels > 0; --numPixels) {
+            addPixelToHistogram(pImg, pHist, numBins);
+        }
+    } else {
+        for( ; numPixels > 0; --numPixels) {
+            if(*pMask == 0){
+                pMask += 4;
+                pImg  += 4;  // Note that otherwise addPixelToHistogram advances pImg by 4
+                continue;
+            }
+            pMask += 4;
+            addPixelToHistogram(pImg, pHist, numBins);
+        }
+    }
+}
+
+void Java_androidx_media_filterpacks_histogram_ChromaHistogramFilter_extractChromaHistogram(
+    JNIEnv* env, jclass clazz, jobject imageBuffer, jobject histogramBuffer, jint hBins, jint sBins)
+{
+    unsigned char* pixelIn = static_cast<unsigned char*>(env->GetDirectBufferAddress(imageBuffer));
+    float* histOut = static_cast<float*>(env->GetDirectBufferAddress(histogramBuffer));
+    int numPixels  = env->GetDirectBufferCapacity(imageBuffer) / 4;  // 4 bytes per pixel
+
+    for (int i = 0; i < hBins * sBins; ++i) histOut[i] = 0.0f;
+
+    int h, s, v;
+    float hScaler = hBins / 256.0f;
+    float sScaler = sBins / 256.0f;
+    for( ; numPixels > 0; --numPixels) {
+      h = *(pixelIn++);
+      s = *(pixelIn++);
+      v = *(pixelIn++);
+      pixelIn++;
+
+      int index = static_cast<int>(s * sScaler) * hBins + static_cast<int>(h * hScaler);
+      histOut[index] += 1.0f;
+    }
+}
+
+void Java_androidx_media_filterpacks_histogram_NewChromaHistogramFilter_extractChromaHistogram(
+    JNIEnv* env, jclass clazz, jobject imageBuffer, jobject histogramBuffer,
+    jint hueBins, jint saturationBins, jint valueBins,
+    jint saturationThreshold, jint valueThreshold) {
+    unsigned char* pixelIn = static_cast<unsigned char*>(env->GetDirectBufferAddress(imageBuffer));
+    float* histOut = static_cast<float*>(env->GetDirectBufferAddress(histogramBuffer));
+    int numPixels  = env->GetDirectBufferCapacity(imageBuffer) / 4;  // 4 bytes per pixel
+
+    // TODO: add check on the size of histOut
+    for (int i = 0; i < (hueBins * saturationBins + valueBins); ++i) {
+      histOut[i] = 0.0f;
+    }
+
+    for( ; numPixels > 0; --numPixels) {
+      int h = *(pixelIn++);
+      int s = *(pixelIn++);
+      int v = *(pixelIn++);
+
+      pixelIn++;
+      // If a pixel that is either too dark (less than valueThreshold) or colorless
+      // (less than saturationThreshold), if will be put in a 1-D value histogram instead.
+
+      int index;
+      if (s > saturationThreshold && v > valueThreshold) {
+        int sIndex = s * saturationBins / 256;
+
+        // Shifting hue index by 0.5 such that peaks of red, yellow, green, cyan, blue, pink
+        // will be at the center of some bins.
+        int hIndex = ((h * hueBins + 128) / 256) % hueBins;
+        index = sIndex * hueBins + hIndex;
+      } else {
+        index =  hueBins * saturationBins + (v * valueBins / 256);
+      }
+      histOut[index] += 1.0f;
+    }
+}