{"id":1435,"date":"2020-08-22T01:25:37","date_gmt":"2020-08-22T01:25:37","guid":{"rendered":"https:\/\/muthu.co\/?p=1435"},"modified":"2020-12-27T13:25:05","modified_gmt":"2020-12-27T13:25:05","slug":"skew-detection-and-correction-of-document-images-using-hough-transform","status":"publish","type":"post","link":"http:\/\/write.muthu.co\/skew-detection-and-correction-of-document-images-using-hough-transform\/","title":{"rendered":"Skew Detection and Correction of Document images using Hough Transform"},"content":{"rendered":"\n

In this post I will be talking about how we can use Hough Transform to detect and correct Skewness of a document image. There have been many research papers published around this problem and it keeps getting published even today on various journals mainly because its still largely an unsolved problem. I had previously written about Skew correction using Horizontal Projections here<\/a> which used the Horizontal projection of an image to indetify the skew angle, The problem with deskewing using Projections is that it fails in many cases where the text may have too many spaces and when the document has less text. This made me look for a better solution and I came across Hough Transform based skew detection technique which is has a better accuracy.<\/p>\n\n\n\n

Hough transform is a feature extraction technique that converts an image from Cartesian to polar coordinates which is how it got “transform” in its name. It can be used to detect lines or a set of collinear points on the image. If you are new to Hough Transform I would recommend you take a look at the video below which is one of the best one on the internet on this topic. <\/p>\n\n\n\n

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