Update README.md

README.md

@@ -77,6 +77,10 @@ unclear" class is that less than 100% and more than 50% of the characters are un
 
 Annotators were employees of National Archives of Finland and ELKA.
 
+### Synthetic data
+
+As a way to increase the amount of training data, we created synthetic data by using this library https://github.com/Belval/TextRecognitionDataGenerator. We collected Finnish books from https://www.gutenberg.org/ and Finnish magazines from https://archive.org/ and created different kinds of textlines. The different kinds include normal textlines, rotated textlines, textlines following a sinosoidal curve and textlines where characters are subjected to noise. 
+
 ### Personal and Sensitive Information 
 
 The dataset is not anonymized, so individuals' names can be found in the dataset.