diff --git a/stitcher.py b/stitcher.py
index 8b48e1b..d4a9017 100644
--- a/stitcher.py
+++ b/stitcher.py
@@ -37,8 +37,8 @@ def xy(filepath):
     x_0, y_0 = min(map(lambda x_y : x_y[0], xys)), min(map(lambda x_y: x_y[1], xys))
     x_1, y_1 = max(map(lambda x_y : x_y[0], xys)), max(map(lambda x_y: x_y[1], xys))
 
-    n_x, n_y = x_1 - x_0, y_1 - y_0
-
+    n_x, n_y = (x_1 + 1) - x_0, (y_1 + 1) - y_0
+    
     out_w, out_h = n_x * tile_w, n_y * tile_h
 
     print('output image size:', out_w, out_h, 'tile size:', tile_w, tile_h)
@@ -54,4 +54,4 @@ def xy(filepath):
     out_img.save(opts.out_file)
 
 if __name__ == '__main__':
-    main()
\ No newline at end of file
+    main()