>How to create a dataset as input to a neural network for a character
>recognition system?
>Asked by Monisha on 4 Jul 2012 at 15:11
>I'm breaking my head on neural networks. I've got the general idea but I
>am unable to work it out with the required tools in matlab (nntool,nprtool).
>The thing is, for training the network, the input has to be 250 images of
>each kannada character and the target vector for each character should be
>such that it is able to indicate which character it is...
>character, 2-second character and son on...
>Does the following make any sense? :) Should the input have a size of
>250x75x75? where each image is of size 75x75 and there are 250 samples of
>each character. How do I do this?
1. Check the literature to see if there is a common method of feature extraction for the purpose of input variable reduction for kannada characters that will substantially reduce the image size (say 25 X 25 or smaller) or just represent the image by a column vector of extracted features.
2.Each reduced image should be converted to a column vector of length 625 = 25*25 using the (:) operator.
3. The resulting size of the input matrix is 625 X 250 which can be partitioned into training, validation and test subsets.
4. The corresponding character indices ( 1 to ?) can be converted to columns of the unit matrix using the function ind2vec.
>How should the target vector look? Maybe the first place of the target
>vector should have 1 and the rest all zeros for the first character.
>Similarly, let it be a column matrix having 1 again in the second place
>and the rest zeros for the second character. Is this right? I have no
>clue.
Correct
> Also, am I right in saying that the input and target vectors need to be
>matlab variables (with .mat extension) for it to be able to fed into the
>network accordingly?
No. Text and Microsoft XL files can be read by ML.
>otherwise I will be unable to load the workspace. So, do I have to write
>another script separately to read the input and target variables?
Not necessarily.
>A basic question - For training the network, the input needs to be
>normalized right? Does this mean that each image has to go through the
>previous steps of binarization and resizing before being fed into the
>neural network for training?
Highly recommended.
>I don't know if I'm making things complex but I am unable to move forward.
>Please give me a hint :( I've exhausted all resources or maybe I'm not
>searching efficiently...
Did the exhausted resources include a Google search of kannada character recognition?
Hope this helps.
Greg
Best Answer