+# Vignette generation and compression #
+
+## Vignette sets ##
+
+The svrtset.py implements the classes `VignetteSet` and
+`CompressedVignetteSet` with the following constructor
+
+```
+__init__(problem_number, nb_samples, batch_size, cuda = False, logger = None)
+```
+
+and the following method to return one batch
+
+```
+(torch.FloatTensor, torch.LongTensor) get_batch(b)
+```
+
+as a pair composed of a 4d 'input' Tensor (i.e. single channel 128x128
+images), and a 1d 'target' Tensor (i.e. Boolean labels).
+
+## Low-level functions ##
+
+The main function for genering vignettes is
+
+```
+torch.ByteTensor svrt.generate_vignettes(int problem_number, torch.LongTensor labels)
+```
+
+where
+
+ * `problem_number` indicates which of the 23 problem to use
+ * `labels` indicates the boolean labels of the vignettes to generate
+
+The returned ByteTensor has three dimensions:
+
+ * Vignette index
+ * Pixel row
+ * Pixel col