CODEWITHSUNDEEP
image-processingimage-recognition
PeakCoder
PeakCoder

Reputation: 852

How to size the image normalization in handwriting recognition?

Handwriting number recognition problem : how can i normalize the hand wiring number image ?someone can help?

Upvotes: 1

Views: 1861

Answers (1)

nicodjimenez
nicodjimenez

Reputation: 1208

Check out how the MNIST dataset is curated here:

http://yann.lecun.com/exdb/mnist/index.html

To quote the relevant section:

The original black and white (bilevel) images from NIST were size normalized to fit in a 20x20 pixel box while preserving their aspect ratio. The resulting images contain grey levels as a result of the anti-aliasing technique used by the normalization algorithm. the images were centered in a 28x28 image by computing the center of mass of the pixels, and translating the image so as to position this point at the center of the 28x28 field.

With some classification methods (particuarly template-based methods, such as SVM and K-nearest neighbors), the error rate improves when the digits are centered by bounding box rather than center of mass. If you do this kind of pre-processing, you should report it in your publications.

Upvotes: 2

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