From ed158acd47e7f479f0958455267b32007c02241e Mon Sep 17 00:00:00 2001
From: heziqi <heziqi36@gmail.com>
Date: Wed, 12 Nov 2014 06:38:45 +0800
Subject: [PATCH] added band average in envi class

---
 envi/bil.h  | 27 +++++++++++++++++++++++++++
 envi/bip.h  | 19 +++++++++++++++++++
 envi/bsq.h  | 19 +++++++++++++++++++
 envi/envi.h | 35 ++++++++++++++++++++++++++++++++++-
 4 files changed, 99 insertions(+), 1 deletion(-)

diff --git a/envi/bil.h b/envi/bil.h
index 16edb2c..c9d9376 100644
--- a/envi/bil.h
+++ b/envi/bil.h
@@ -727,6 +727,33 @@ public:
 		return true;
 	}
 
+	//calculate the average band value
+	bool band_avg(T* p){
+		unsigned long long XZ = R[0] * R[2];
+		T* temp = (T*)malloc(sizeof(T) * XZ);
+		T* line = (T*)malloc(sizeof(T) * R[0]);
+
+		for (unsigned i = 0; i < R[1]; i++){
+			getY(temp, i);
+			//initialize x-line
+			for (unsigned j = 0; j < R[0]; j++){
+				line[j] = 0;
+			}
+			unsigned c = 0;
+			for (unsigned j = 0; j < R[2]; j++){
+				for (unsigned k = 0; k < R[0]; k++){
+					line[k] += temp[c] / (T)R[2];
+					c++;
+				}
+			}
+			for (unsigned j = 0; j < R[0]; j++){
+				p[j + i * R[0]] = line[j];
+			}
+		}
+		free(temp);
+		return true;
+	}
+
 	//close the file
 	bool close(){
 		file.close();
diff --git a/envi/bip.h b/envi/bip.h
index c1e9b61..7e21053 100644
--- a/envi/bip.h
+++ b/envi/bip.h
@@ -821,6 +821,25 @@ public:
 		return true;
 	}
 
+	//calculate the average band of the file
+	bool band_avg(T* p){
+		unsigned long long XY = R[0] * R[1];
+		//get every pixel and calculate average value
+		T* temp = (T*)malloc(sizeof(T) * R[2]);
+		T sum;
+		for (unsigned i = 0; i < XY; i++){
+			pixel(temp, i);
+			//calculate the sum value of every value
+			sum = 0;		//initialize sum value
+			for (unsigned j = 0; j < R[2]; j++){
+				sum += temp[j]/(T)R[2];
+			}
+			p[i] = sum;
+		}
+		free(temp);
+		return true;
+	}
+
 	//close the file
 	bool close(){
 		file.close();
diff --git a/envi/bsq.h b/envi/bsq.h
index 099df79..183b379 100644
--- a/envi/bsq.h
+++ b/envi/bsq.h
@@ -663,6 +663,25 @@ public:
 		return true;
 	}
 
+	//calculate the average band
+	bool band_avg(T* p){
+		unsigned long long XY = R[0] * R[1];
+		T* temp = (T*)malloc(sizeof(T) * XY);
+		//initialize p
+		band_index(p, 0);
+		for (unsigned j = 0; j < XY; j++){
+			p[j] /= (T)R[2];
+		}
+		//get every band and add them all
+		for (unsigned i = 1; i < R[2]; i++){
+			band_index(temp, i);
+			for (unsigned j = 0; j < XY; j++){
+				p[j] += temp[j]/(T)R[2];
+			}
+		}
+		free(temp);
+		return true;
+	}
 
 	//close the file
 	bool close(){
diff --git a/envi/envi.h b/envi/envi.h
index b2e2e4b..c45fce3 100644
--- a/envi/envi.h
+++ b/envi/envi.h
@@ -642,7 +642,40 @@ public:
 		return true;
 	}
 
-
+	//calculate band average
+	bool band_avg(void * p){
+		if (header.interleave == envi_header::BSQ){
+			if (header.data_type == envi_header::float32)
+				return ((bsq<float>*)file)->band_avg((float*)p);
+			else if (header.data_type == envi_header::float64)
+				return ((bsq<double>*)file)->band_avg((double*)p);
+			else{
+				std::cout << "ERROR: unidentified data type" << std::endl;
+				exit(1);
+			}
+		}
+		else if (header.interleave == envi_header::BIL){
+			if (header.data_type == envi_header::float32)
+				return ((bil<float>*)file)->band_avg((float*)p);
+			else if (header.data_type == envi_header::float64)
+				return ((bil<double>*)file)->band_avg((double*)p);
+			else{
+				std::cout << "ERROR: unidentified data type" << std::endl;
+				exit(1);
+			}
+		}
+		else if (header.interleave == envi_header::BIP){
+			if (header.data_type == envi_header::float32)
+				return ((bip<float>*)file)->band_avg((float*)p);
+			else if (header.data_type == envi_header::float64)
+				return ((bip<double>*)file)->band_avg((double*)p);
+			else{
+				std::cout << "ERROR: unidentified data type" << std::endl;
+				exit(1);
+			}
+		}
+		return false;
+	}
 
 };
 
--
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