added a crop function to stim::image

David Mayerich
1 parent e3b53161
Showing 2 changed files with 15 additions and 2 deletions Show diff stats
stim/envi/agilent_binary.h
stim/image/image.h
@@ -125,7 +125,7 @@ public:
 		infile.read((char*)ptr, bytes());				//read the data		
 		infile.close();
 		Z[0] = 1;
-		Z[1] = R[2];
+		Z[1] = (double)R[2];
 	}
  
 	void save(std::string filename){
@@ -480,7 +480,6 @@ public:
 				max_val = img[n];
 			}
 		}
-
 		return max_val;
 	}
  
@@ -508,6 +507,20 @@ public:
 		return r;								//return the inverted image
 	}
  
+	image<T> crop(size_t x0, size_t y0, size_t w, size_t h){
+		image<T> result(w, h, C());								//create the output cropped image
+
+		size_t srci;
+		size_t dsti;
+		size_t line_bytes = w * C();							//calculate the number of bytes in a line
+		for (size_t yi = 0; yi < h; yi++) {						//for each row in the cropped image
+			srci = (y0 + yi) * X() * C() + x0 * C();			//calculate the source index
+			dsti = yi * w * C();								//calculate the destination index
+			memcpy(&result.img[dsti], &img[srci], line_bytes);	//copy the data
+		}
+		return result;
+	}
+
 	image<T> srgb2lab(){
 		std::cout<<"ERROR stim::image::srgb2lab - function has been broken, re-implement."<<std::endl;
 		exit(1);