From: Skullheadx <admonty1@gmail.com>
Date: Wed, 20 Nov 2024 01:51:03 +0000 (-0500)
Subject: Decode the format information adjacent to the upper left finder pattern
X-Git-Url: http://git.skullheadx.com/nixos/static/gitweb.css?a=commitdiff_plain;h=22beb4bb3ee0aa43fa94042f15cf96a96e5c91f3;p=qrcodescanner.git

Decode the format information adjacent to the upper left finder pattern
---

diff --git a/camera.cpp b/camera.cpp
index 0d20f12..7ce54fd 100644
--- a/camera.cpp
+++ b/camera.cpp
@@ -3,15 +3,23 @@
 #include <cassert>
 #include <vector>
 
-void read_words_from_file(char const *filename, std::vector<std::vector<bool>> &symbol);
+void print(std::vector<bool> &vec);
 void print(std::vector<std::vector<bool>> &symbol);
+void vec_xor(std::vector<bool> &v1, const std::vector<bool> v2);
+unsigned int distance(std::vector<bool> &v1, const std::vector<bool> &v2);
+void read_words_from_file(char const *filename, std::vector<std::vector<bool>> &symbol);
+
+std::vector<bool> get_format_info(std::vector<std::vector<bool>> &symbol);
 
 int main(){
 	std::vector<std::vector<bool>> symbol(21, std::vector<bool>(21,0));
 
 	read_words_from_file("output.pbm", symbol);
 	print(symbol);
+	
+	std::vector<bool> format_info = get_format_info(symbol);
 
+	print(format_info);
 	
 	return 0;
 }
@@ -24,6 +32,106 @@ void print(std::vector<std::vector<bool>> &symbol){
 	      }
 		std::cout << std::endl;
 	}
+	std::cout << std::endl;
+}
+
+void print(std::vector<bool> &vec){
+	for (auto i : vec){
+		std::cout << i;
+	}
+	std::cout << std::endl;
+}
+
+void vec_xor(std::vector<bool> &v1, const std::vector<bool> v2){
+	for (std::size_t i{0}; i < v1.size(); ++i){
+		v1[i] = v1[i] ^ v2[i];
+	}
+}
+
+unsigned int distance(std::vector<bool> &v1, const std::vector<bool> &v2){
+	unsigned int dist{0};
+	for (std::size_t i{0}; i < v1.size(); ++i){
+		if (v1[i] != v2[i]){
+			++dist;
+		}
+
+		if (dist > 3){
+			return dist;
+		}
+	}
+	return dist;
+}
+		
+
+std::vector<bool> get_format_info(std::vector<std::vector<bool>> &symbol){
+	std::vector<bool> format_info(15,0);
+	for (std::size_t row{0}, counter{14}; row < 21; ++row){
+		if (row == 6 || (row >= 9 && row <= 13)){
+			continue;
+		}
+		format_info[counter] = (symbol[row][8]);
+		--counter;
+	}
+
+	std::vector<std::vector<bool>> valid_bit_format_info = {
+		{0,0,0,0,0,0,0,0,0,0,0,0,0,0,0},
+		{0,0,0,0,1,0,1,0,0,1,1,0,1,1,1},
+		{0,0,0,1,0,1,0,0,1,1,0,1,1,1,0},
+		{0,0,0,1,1,1,1,0,1,0,1,1,0,0,1},
+		{0,0,1,0,0,0,1,1,1,1,0,1,0,1,1},
+		{0,0,1,0,1,0,0,1,1,0,1,1,1,0,0},
+		{0,0,1,1,0,1,1,1,0,0,0,0,1,0,1},
+		{0,0,1,1,1,1,0,1,0,1,1,0,0,1,0},
+		{0,1,0,0,0,1,1,1,1,0,1,0,1,1,0},
+		{0,1,0,0,1,1,0,1,1,1,0,0,0,0,1},
+		{0,1,0,1,0,0,1,1,0,1,1,1,0,0,0},
+		{0,1,0,1,1,0,0,1,0,0,0,1,1,1,1},
+		{0,1,1,0,0,1,0,0,0,1,1,1,1,0,1},
+		{0,1,1,0,1,1,1,0,0,0,0,1,0,1,0},
+		{0,1,1,1,0,0,0,0,1,0,1,0,0,1,1},
+		{0,1,1,1,1,0,1,0,1,1,0,0,1,0,0},
+		{1,0,0,0,0,1,0,1,0,0,1,1,0,1,1},
+		{1,0,0,0,1,1,1,1,0,1,0,1,1,0,0},
+		{1,0,0,1,0,0,0,1,1,1,1,0,1,0,1},
+		{1,0,0,1,1,0,1,1,1,0,0,0,0,1,0},
+		{1,0,1,0,0,1,1,0,1,1,1,0,0,0,0},
+		{1,0,1,0,1,1,0,0,1,0,0,0,1,1,1},
+		{1,0,1,1,0,0,1,0,0,0,1,1,1,1,0},
+		{1,0,1,1,1,0,0,0,0,1,0,1,0,0,1},
+		{1,1,0,0,0,0,1,0,1,0,0,1,1,0,1},
+		{1,1,0,0,1,0,0,0,1,1,1,1,0,1,0},
+		{1,1,0,1,0,1,1,0,0,1,0,0,0,1,1},
+		{1,1,0,1,1,1,0,0,0,0,1,0,1,0,0},
+		{1,1,1,0,0,0,0,1,0,1,0,0,1,1,0},
+		{1,1,1,0,1,0,1,1,0,0,1,0,0,0,1},
+		{1,1,1,1,0,1,0,1,1,0,0,1,0,0,0},
+		{1,1,1,1,1,1,1,1,1,1,1,1,1,1,1},
+	};
+	
+	std::vector<bool> mask = {1,0,1,0,1,0,0,0,0,0,1,0,0,1,0};
+	vec_xor(format_info, mask);
+
+	unsigned int min_dist = distance(format_info, valid_bit_format_info[0]);
+	std::size_t min_dist_index{0};
+	for (std::size_t i{0}; i < valid_bit_format_info.size(); ++i){
+		unsigned int curr_dist = distance(format_info, valid_bit_format_info[i]);
+		if (curr_dist <= min_dist){
+			min_dist = curr_dist;
+			min_dist_index = i;
+			if (curr_dist == 0){
+				break;
+			}
+		}
+	}
+	//std::cout << min_dist << " " << std::endl; 
+	if (min_dist <= 3){
+		format_info = valid_bit_format_info[min_dist_index];
+	}
+	else{
+		throw std::runtime_error("format information incorrectly scanned!");
+	}
+
+	return format_info;
 }
 
 void read_words_from_file(char const *filename, std::vector<std::vector<bool>> &symbol) {
diff --git a/tablec1.txt b/tablec1.txt
new file mode 100644
index 0000000..0c33e37
--- /dev/null
+++ b/tablec1.txt
@@ -0,0 +1,32 @@
+000000000000000
+000010100110111
+000101001101110
+000111101011001
+001000111101011
+001010011011100
+001101110000101
+001111010110010
+010001111010110
+010011011100001
+010100110111000
+010110010001111
+011001000111101
+011011100001010
+011100001010011
+011110101100100
+100001010011011
+100011110101100
+100100011110101
+100110111000010
+101001101110000
+101011001000111
+101100100011110
+101110000101001
+110000101001101
+110010001111010
+110101100100011
+110111000010100
+111000010100110
+111010110010001
+111101011001000
+111111111111111