Commit f3de42f83d400e423932a2e28a72d9ee65ab704d
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added stim_spectral.py
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| 1 | +# -*- coding: utf-8 -*- | |
| 2 | +""" | |
| 3 | +Created on Sun Jul 23 13:52:22 2017 | |
| 4 | + | |
| 5 | +@author: david | |
| 6 | +""" | |
| 7 | +import numpy | |
| 8 | + | |
| 9 | +#sift a 2D hyperspectral image into a PxB matrix where P is the number of pixels and B is the number of bands | |
| 10 | +def sift2(I, mask = []): | |
| 11 | + | |
| 12 | + #get the shape of the input array | |
| 13 | + S = I.shape | |
| 14 | + | |
| 15 | + #convert that array into a 1D matrix | |
| 16 | + M = numpy.reshape(I, (S[0], S[1] * S[2])) | |
| 17 | + | |
| 18 | + #gif no mask is provided, just return all pixels | |
| 19 | + if mask == []: | |
| 20 | + return M | |
| 21 | + | |
| 22 | + #if a mask is provided, only return pixels corresponding to that mask | |
| 23 | + flatmask = numpy.reshape(mask, (S[1] * S[2])) | |
| 24 | + i = numpy.flatnonzero(flatmask) #get the nonzero indices | |
| 25 | + return M[:, i] #return pixels corresponding to the masked values | |
| 26 | + | |
| 27 | +def unsift2(M, mask): | |
| 28 | + | |
| 29 | + #get the size of the input matrix | |
| 30 | + S = M.shape | |
| 31 | + | |
| 32 | + #count the number of nonzero values in the mask | |
| 33 | + nnz = numpy.count_nonzero(mask) | |
| 34 | + | |
| 35 | + #the number of masked values should be the same as the number of pixels in the input matrix | |
| 36 | + if len(S) == 1: | |
| 37 | + if not S[0] == nnz: | |
| 38 | + print("ERROR: expected " + str(nnz) + " pixels based on the mask but there are " + str(S[0]) + " in the matrix.") | |
| 39 | + elif not S[1] == nnz: | |
| 40 | + print("ERROR: expected " + str(nnz) + " pixels based on the mask but there are " + str(S[1]) + " in the matrix.") | |
| 41 | + | |
| 42 | + | |
| 43 | + i = numpy.nonzero(mask) | |
| 44 | + | |
| 45 | + if len(S) == 1: | |
| 46 | + I = numpy.zeros((1, mask.shape[0], mask.shape[1]), dtype=M.dtype) | |
| 47 | + else: | |
| 48 | + I = numpy.zeros((M.shape[0], mask.shape[0], mask.shape[1]), dtype=M.dtype) | |
| 49 | + I[:, i[0], i[1]] = M | |
| 50 | + return I | |
| 51 | + | |
| 52 | +#create a function that sifts a color image | |
| 53 | +#input: image name, mask | |
| 0 | 54 | \ No newline at end of file | ... | ... |