Files
scikit-image/scikits/image/opencv/opencv_backend.pyx
T
2010-11-07 01:12:54 +02:00

299 lines
10 KiB
Cython

import ctypes
import numpy as np
cimport numpy as np
from cpython cimport *
from opencv_constants import *
from opencv_type cimport *
from _libimport import cv, cxcore
if cv is None:
raise RuntimeError("Could not load libcv")
if cxcore is None:
raise RuntimeError("Could not load libcxcore")
# setup numpy tables for this module
np.import_array()
#-----------------------------------------------------------------------------
# Data Type Handling
#-----------------------------------------------------------------------------
# for some reason these have to declared as dtype objects rather than just the
# dtype itself....
UINT8 = np.dtype('uint8')
INT8 = np.dtype('int8')
UINT16 = np.dtype('uint16')
INT16 = np.dtype('int16')
INT32 = np.dtype('int32')
FLOAT32 = np.dtype('float32')
FLOAT64 = np.dtype('float64')
cdef int IPL_DEPTH_SIGN = 0x80000000
cdef int IPL_DEPTH_8U = 8
cdef int IPL_DEPTH_8S = (IPL_DEPTH_SIGN | 8)
cdef int IPL_DEPTH_16U = 16
cdef int IPL_DEPTH_16S = (IPL_DEPTH_SIGN | 16)
cdef int IPL_DEPTH_32S = (IPL_DEPTH_SIGN | 32)
cdef int IPL_DEPTH_32F = 32
cdef int IPL_DEPTH_64F = 64
# I'd like a better to associate the IPL data type flag to the proper numpy
# types without using a dictionary.
_ipltypes = {UINT8: IPL_DEPTH_8U, INT8: IPL_DEPTH_8S, UINT16: IPL_DEPTH_16U,
INT16: IPL_DEPTH_16S, INT32: IPL_DEPTH_32S, FLOAT32: IPL_DEPTH_32F,
FLOAT64: IPL_DEPTH_64F}
#-----------------------------------------------------------------------------
# Utility functions for IplImage creation, array validation, etc...
#-----------------------------------------------------------------------------
cdef int IPLIMAGE_SIZE = sizeof(IplImage)
# a function to convert from IplImage to cvMat
# this eliminates the need for a second populate function
# for CvMat
ctypedef CvMat* (*cvGetMatPtr)(IplImage*, CvMat*, int*, int)
cdef cvGetMatPtr c_cvGetMat
c_cvGetMat = (<cvGetMatPtr*><size_t>ctypes.addressof(cxcore.cvGetMat))[0]
cdef void populate_iplimage(np.ndarray arr, IplImage* img):
# The numpy array should be validated with the validate_array
# function before using this function.
# This function assumes that the array has successfully passed
# validation
# everything that will never change
img.nSize = IPLIMAGE_SIZE
img.ID = 0
img.dataOrder = 0
img.origin = 0
img.roi = NULL
img.maskROI = NULL
img.imageId = NULL
img.tileInfo = NULL
cdef int ndim = arr.ndim
cdef np.npy_intp* shape = arr.shape
cdef np.npy_intp* strides = arr.strides
# nChannels is essentially the value of np.shape[2] of a 3D numpy array
# for a 2D array, nChannels is 1
if ndim == 1:
# Might happen for a 1D vector
img.nChannels = 1
img.width = 1
else:
if ndim == 2:
img.nChannels = 1
else:
img.nChannels = shape[2]
img.width = shape[1]
img.height = shape[0]
img.widthStep = strides[0]
img.depth = _ipltypes[arr.dtype]
img.imageSize = arr.nbytes
img.imageData = <char*>arr.data
# really doesn't matter what this is set to, because opencv only uses it to
# deallocate images, but it will never attempt to deallocate images we
# create ourselves.
img.imageDataOrigin = <char*>NULL
cdef CvMat* cvmat_ptr_from_iplimage(IplImage* arr):
# this functions takes an IplImage* and returns a CvMat*
# it is designed so that we dont need a separate populate_cvmat
# function, or deal with OpenCV magic values. However, it needs to create a
# CvMat header to pass to the opencv conversion routine.
# This means that you have to call PyMem_Free on the CvMat* when you're
# done with it.
cdef CvMat* mat_hdr = <CvMat*>PyMem_Malloc(sizeof(CvMat))
mat_hdr = c_cvGetMat(arr, mat_hdr, NULL, 0)
return mat_hdr
cdef int validate_array(np.ndarray arr) except -1:
# this assertion prevents the use of slices, so
# we need to be more creative about how to deal
# with non-contiguous arrays
#assert PyArray_ISCONTIGUOUS(arr), 'Array must be contiguous'
if arr.ndim != 2 and arr.ndim != 3:
raise ValueError('Arrays must have either 2 or 3 dimensions')
if arr.ndim == 3:
if arr.shape[2] > 4:
raise ValueError('A 3D array must have 4 or less channels')
if arr.dtype not in _ipltypes:
raise ValueError('Arrays must have one of the following dtypes: '
'uint8, int8, int16, int32, float32, float64')
return 1
cdef int assert_dtype(np.ndarray arr, dtypes) except -1:
if arr.dtype not in dtypes:
raise ValueError('Unsupported dtype for this operation. \
Supported dtypes are %s' % str(dtypes))
return 1
cdef int assert_ndims(np.ndarray arr, dims) except -1:
if arr.ndim not in dims:
raise ValueError('Incorrect number of dimensions')
return 1
cdef int assert_nchannels(np.ndarray arr, channels) except -1:
cdef int nchannels
if arr.ndim == 2:
nchannels = 1
else:
nchannels = arr.shape[2]
if nchannels not in channels:
raise ValueError('Incorrect number of channels')
return 1
cdef int assert_same_dtype(np.ndarray arr1, np.ndarray arr2) except -1:
if arr1.dtype != arr2.dtype:
raise ValueError('dtypes not same')
return 1
cdef int assert_same_shape(np.ndarray arr1, np.ndarray arr2) except -1:
if not np.PyArray_SAMESHAPE(arr1, arr2):
raise ValueError('arrays not same shape')
return 1
cdef int assert_same_width_and_height(np.ndarray arr1, np.ndarray arr2) \
except -1:
cdef np.npy_intp* shape1 = arr1.shape
cdef np.npy_intp* shape2 = arr2.shape
if (shape1[0] != shape2[0]) or (shape1[1] != shape2[1]):
raise ValueError('Arrays must have same width and height')
return 1
cdef int assert_like(np.ndarray arr1, np.ndarray arr2) except -1:
assert_same_dtype(arr1, arr2)
assert_same_shape(arr1, arr2)
return 1
cdef int assert_not_sharing_data(np.ndarray arr1, np.ndarray arr2) except -1:
if arr1.data == arr2.data:
raise ValueError('In place operation not supported. Make sure \
the out array is not just a view of src array')
return 1
#-----------------------------------------------------------------------------
# NumPy array convienences
#-----------------------------------------------------------------------------
cdef np.ndarray new_array(int ndim, np.npy_intp* shape, dtype):
# need to incref because numpy will apprently steal a dtype reference
Py_INCREF(<object>dtype)
return PyArray_Empty(ndim, shape, dtype, 0)
cdef np.ndarray new_array_like(np.ndarray arr):
# need to incref because numpy will apprently steal a dtype reference
Py_INCREF(<object>arr.dtype)
return PyArray_Empty(arr.ndim, arr.shape, arr.dtype, 0)
cdef np.ndarray new_array_like_diff_dtype(np.ndarray arr, dtype):
# need to incref because numpy will apprently steal a dtype reference
Py_INCREF(<object>dtype)
return PyArray_Empty(arr.ndim, arr.shape, dtype, 0)
cdef np.npy_intp* clone_array_shape(np.ndarray arr):
# make sure you call PyMem_Free after you're done with the shape
cdef int ndim = arr.ndim
cdef np.npy_intp* shape = <np.npy_intp*>PyMem_Malloc(
ndim * sizeof(np.npy_intp))
cdef int i
for i in range(ndim):
shape[i] = arr.shape[i]
return shape
cdef np.npy_intp get_array_nbytes(np.ndarray arr):
cdef np.npy_intp nbytes = np.PyArray_NBYTES(arr)
return nbytes
#-------------------------------------------------------------------------------
# OpenCV convienences
#-------------------------------------------------------------------------------
cdef CvPoint2D32f* array_as_cvPoint2D32f_ptr(np.ndarray arr):
cdef CvPoint2D32f* point2Darr
point2Darr = <CvPoint2D32f*>arr.data
return point2Darr
cdef CvTermCriteria get_cvTermCriteria(int iterations, double epsilon):
cdef CvTermCriteria crit
if iterations and epsilon:
crit.type = <int>(CV_TERMCRIT_ITER | CV_TERMCRIT_EPS)
crit.max_iter = iterations
crit.epsilon = epsilon
elif iterations and not epsilon:
crit.type = <int>CV_TERMCRIT_ITER
crit.max_iter = iterations
crit.epsilon = 0.
else:
crit.type = <int>CV_TERMCRIT_EPS
crit.max_iter = 0
crit.epsilon = epsilon
return crit
ctypedef IplConvKernel* (*cvCreateStructuringElementExPtr)(int, int, int, int,
int, int*)
cdef cvCreateStructuringElementExPtr c_cvCreateStructuringElementEx
c_cvCreateStructuringElementEx = (<cvCreateStructuringElementExPtr*><size_t>
ctypes.addressof(cv.cvCreateStructuringElementEx))[0]
ctypedef void (*cvReleaseStructuringElementPtr)(IplConvKernel**)
cdef cvReleaseStructuringElementPtr c_cvReleaseStructuringElement
c_cvReleaseStructuringElement = (<cvReleaseStructuringElementPtr*><size_t>
ctypes.addressof(cv.cvReleaseStructuringElement))[0]
cdef IplConvKernel* get_IplConvKernel_ptr_from_array(np.ndarray arr, anchor) \
except NULL:
# make sure you call free_IplConvKernel you're done with the kernel
validate_array(arr)
assert_ndims(arr, [2])
assert_dtype(arr, [INT32])
cdef int rows
cdef int cols
cdef int anchorx
cdef int anchory
if anchor is not None:
assert len(anchor) == 2, 'anchor must be (x, y) tuple'
anchorx = <int>anchor[0]
anchory = <int>anchor[1]
assert (anchorx < arr.shape[1]) and (anchorx >= 0) \
and (anchory < arr.shape[0]) and (anchory >= 0), \
'anchor point must be inside kernel'
else:
anchorx = <int>(arr.shape[1] / 2.)
anchory = <int>(arr.shape[0] / 2.)
rows = arr.shape[0]
cols = arr.shape[1]
cdef int* values = <int*>arr.data
# this function copies the data from the array into (i'm guessing)
# aligned memory. Since this is using opencv memory management
# the free_IplConvKernel function makes the appropriate calls to free it
cdef IplConvKernel* iplkernel = \
c_cvCreateStructuringElementEx(cols, rows, anchorx, anchory,
CV_SHAPE_CUSTOM, values)
return iplkernel
cdef void free_IplConvKernel(IplConvKernel* iplkernel):
c_cvReleaseStructuringElement(&iplkernel)
#-------------------------------------------------------------------------------
# Other convienences
#-------------------------------------------------------------------------------