+/* This module effectively implements a form of picture-in-picture.
+ * - The outer picture is called the canvas.
+ * - The innter picture is callsed the subpicture.
+ *
+ * NB, all of the following operatons take into account aspect ratio
+ *
+ * A canvas is of canvas_{width,height}.
+ * In Pad mode:
+ * - The subpicture is upconverted with a inverse scalefactor of:
+ * (The size of subpicture's largest dimension)
+ * --------------------------------------------
+ * (The size of canvas's equivalent dimension)
+ *
+ * Ie, The subpicture's largest dimension is made equal to the
+ * equivalent canvas dimension.
+ *
+ * - The upconverted subpicture's smallest dimension is then padded
+ * to make the upconverted subpicture have the same dimensions of
+ * the canvas.
+ *
+ * In Crop mode:
+ * - The subpicture is upconverted with an inverse scalefactor of:
+ * (The size of subpicture's smallest dimension)
+ * --------------------------------------------
+ * (The size of canvas's equivalent dimension)
+ *
+ * Ie, The subpicture's smallest dimension is made equal to the
+ * equivalent canvas dimension. (The subpicture will then be
+ * larger than the canvas)
+ *
+ * - The upconverted subpicture's largest dimension is then cropped
+ * to make the upconverted subpicture have the same dimensions of
+ * the canvas.
+ */
+
+/* NB, use of `padd' in this module is a 16-17th Century spelling of `pad' */
+
+#define WIDTH_TEXT N_( "Output width" )