diff --git a/frame.cpp b/frame.cpp
index efdef40..f61a870 100644
--- a/frame.cpp
+++ b/frame.cpp
@@ -1,8 +1,16 @@
-/*  frame.cpp
- *  Takes a black/white (1bpp) PNM ASCII-armored image as input,
- *  and produces the frame.S assembly code to draw it
- *  as an analog video signal for this project's kernel.
- * */
+/**
+ * @file frame.cpp
+ * @author giomba@glgprograms.it
+ * @brief Transform a black and white PNM image into the assembly code for the video generator.
+ * 
+ * Takes a black/white (1bpp) PNM ASCII-armored image as input,
+ * and produces the frame.S assembly code to draw it
+ * as an analog video signal for this project's kernel.
+ * 
+ * @copyright Copyright retrofficina.glgprograms.it (c) 2021-2022
+ * 
+ */
+
 #include <iostream>
 #include <fstream>
 #include <sstream>
@@ -16,6 +24,7 @@ enum ExitStatus {
 
 int main(int argc, char** argv) {
     if (argc < 2) {
+        std::cerr << "Usage: " << argv[0] << " <FILE>" << std::endl;
         return BAD_ARGUMENT;
     }
     const int images = argc - 1;