I HAVE A DREAM

.gitignore

@@ -1,6 +1,3 @@
-*.jpg
-*.png
-*.gif
 *.zip
 *.pdf
 *.txt

display_graph.py

@@ -11,12 +11,23 @@
 ## Build graph
 print('Rebuilding graph... ', end='', flush=True)
 
-with open('image_as_graph.txt', 'rb') as input:
-    next(input, '')
+with open('image_to_graph.out', 'rb') as input:
+    dims = next(input, '').split()
+    rows = int(dims[0])
+    cols = int(dims[1])
     G = nx.read_edgelist(input, nodetype=int)
 
 print('Done.')
 
+print('Making layout... ', end='', flush=True)
+
+layout = {}
+for row in range(rows):
+    for col in range(cols):
+        layout[row*cols+col] = [col,rows-row]
+
+print('Done.')
+
 ## Check results
-nx.draw_networkx_edges(G, pos=nx.spring_layout(G))
+nx.draw_networkx_edges(G, pos=layout)
 pl.show()

image_to_graph.cc

@@ -10,7 +10,9 @@
 #include <opencv2/highgui.hpp>
 
 // pixel neighborhood size
-#define NSPAN 15
+#ifndef NSPAN
+#define NSPAN 5
+#endif
 
 int main(int argc, char *argv[])
 {
@@ -72,7 +74,7 @@ int main(int argc, char *argv[])
                     uchar neighbour_value = image.data[irow_n*image.cols+icol_n];
 
                     // If the pixels have similarity greater than a certain measure, link them
-                    if (255-std::abs(value-neighbour_value) >= 245) {
+                    if (255-std::abs(value-neighbour_value) >= 253) {
                         igraph_vector_push_back(&edges, irow*image.cols+icol);
                         igraph_vector_push_back(&edges, irow_n*image.cols+icol_n);
                     }
@@ -95,7 +97,10 @@ int main(int argc, char *argv[])
         using std::ofstream;
         ofstream graph_file;  // output graph to this file
 
-        graph_file.open("image_as_graph.txt", ofstream::out|ofstream::trunc);
+        graph_file.open("image_to_graph.out", ofstream::out|ofstream::trunc);
+
+        // Downsampled image dims outputted as header
+        graph_file << image.rows << " " << image.cols << std::endl;
 
         // Graph is outputted to file as an edgelist
         for (igraph_integer_t iedge = 0; iedge < igraph_ecount(&graph); iedge++) {