diff --git a/stim/envi/envi.h b/stim/envi/envi.h
index bca10ea..a19652a 100644
--- a/stim/envi/envi.h
+++ b/stim/envi/envi.h
@@ -83,8 +83,22 @@ public:
 		return true;
 	}
 
+	static size_t file_size(std::string filename){
+		FILE *p_file = NULL;
+		p_file = fopen(filename.c_str(),"rb");
+		if(!p_file){
+			std::cout<<"ERROR: could not open "<<filename<<std::endl;
+			exit(1);
+		}
+		fseek(p_file,0,SEEK_END);
+		size_t size = ftell(p_file);
+		fclose(p_file);
+		return size;
+	}
+
 	//test to determine if the specified file is an ENVI file
 	static bool is_envi(std::string fname, std::string hname = ""){
+		return true;
 		stim::filename data_file(fname);
 		stim::filename header_file;
 		if(hname == ""){								//if the header isn't provided
@@ -97,11 +111,13 @@ public:
 		if(H.load(header_file) == false)				//load the header file, if it doesn't load return false
 			return false;
 		size_t targetBytes = H.data_bytes();			//get the number of bytes that SHOULD be in the data file
-		std::ifstream infile(data_file.str(), std::ifstream::ate | std::ifstream::binary);			//load the data file
-		if(!infile) return false;						//if the data file doesn't load, return false
-		size_t bytes = infile.tellg();					//get the number of actual bytes in the file
+		//std::ifstream infile(data_file.str(), std::ifstream::binary);			//load the data file
+		//if(!infile) return false;						//if the data file doesn't load, return false
+		//size_t bytes = infile.tellg();					//get the number of actual bytes in the file
+		size_t bytes = file_size(fname);
 		if(bytes != targetBytes) return false;			//if the data doesn't match the header, return false
 		return true;									//otherwise everything looks fine
+
 	}
 	
 
diff --git a/stim/envi/hsi.h b/stim/envi/hsi.h
index 3b60602..127158b 100644
--- a/stim/envi/hsi.h
+++ b/stim/envi/hsi.h
@@ -142,7 +142,7 @@ public:
 	void mask_finite(unsigned char* out_mask, unsigned char* mask, bool PROGRESS = false){
 		size_t XY = X() * Y();
 		if(mask == NULL)												//if no mask is provided
-			memset(mask, 255, XY * sizeof(unsigned char));				//initialize the mask to 255
+			memset(out_mask, 255, XY * sizeof(unsigned char));				//initialize the mask to 255
 		else															//if a mask is provided
 			memcpy(out_mask, mask, XY * sizeof(unsigned char));			//initialize the current mask to that one
 		T* page = (T*)malloc(R[0] * R[1] * sizeof(T));		//allocate space for a page of data
--
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