ImageHistogram must be moved to a new package, different of image_cleaning

april-org / april-ann

APRIL-ANN toolkit (A Pattern Recognizer In Lua with ANNs). This toolkit incorporates ANN algorithms (as dropout, stacked denoising auto-encoders, convolutional NNs), with other pattern recognition methods as HMMs among others. Additionally, in experimental stage, it is possible to perform automatic differentiation, for advanced ML research.

http://april-org.github.io/april-ann/

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ImageHistogram must be moved to a new package, different of image_cleaning #31

Closed pakozm closed 11 years ago

pakozm commented 11 years ago

Ths histogram per se is interesting, independently of the image cleaning methods.

joapaspe commented 11 years ago

I will change it. Thank you.

pakozm commented 11 years ago

Would be interesting the computation of histograms from matrices instead of images? I'm thinking, as example, in plot purposes. You could produce a matrix of data, and compute the histogram, as it is done in matlab.

joapaspe commented 11 years ago

It would be easy to adapt the code to work with matrices. We can change the name to histograms and then add wrapper functions to work with images.

pakozm commented 11 years ago

Ok, I like it, we could use Lua wrappers which transforms the matrix into a image. Some issues need to be taken into consideration:

A matrix is a complex object which contains a memory pointer which could be shared among several number of matrices. It is necessary to check if the memory of the matrix is contiguous, and if not, to produce a clone of the given matrix before converting it to a Image.
The matrix-based histogram functions (wrappers of Image-based functions), must be renamed because the horizontal or vertical histograms has no sense with matrices. So, it is possible to compute two kind of histograms:
- histogram: computes the histogram from ALL the data contained in the matrix.
- given dimension histogram: computes the histogram of the given dimension at every possible position of the matrix, similar to sum, max and min methods in matrix.

joapaspe commented 11 years ago

I was thinking on the opposite. Have a general function for histograms to work with matrices, and then to add a wrapper which takes the image and extract the 2D matrix and dimensions and calls to the general matrix function. The horizontal and vertical histogram can be also wrappers of image, because they make sense in this context. In deed, we can let the image_histograms as a wrapper and then to have another package called histogram that works with matrices. Anyway, image_histogram shouldn't be in image_cleaning.

joapaspe commented 11 years ago

Finally it is better to create another Histogram package for more general data since ImageHistograms use Integral Image for efficient computation of the histograms.