我正在尝试拍摄一个或三个 channel 的二维图像,并使用 vtkImageActor
在 VTK 中显示它们。据我了解,可以通过调用 vtkImageActor
上的 SetImageData
并提供 vtkImageData
实例来更新要显示的当前帧。
我已经设置了我的可视化工具,如下所示。但是,我不确定如何从 numpy 数组构建 vtkImageData
对象(这将进入 updateFrames
方法)。我的 numpy 数组的类型是 np.uint8_t
。
我正在使用 VTK8.0、Python 3.6 和 Numpy 1.13.1
class VTKStreamVisualiser:
def __init__(self, displayRGB):
self.__displayRGB = displayRGB
self.__started = False
#Setup window.
self.__renderWindow = vtk.vtkRenderWindow()
self.__renderWindowInteractor = vtk.vtkRenderWindowInteractor()
self.__renderWindowInteractor.SetRenderWindow(self.__renderWindow)
#To store renderers and actors.
self.__renderers = []
self.__actors = []
#Initialise to None to check if ready when invoking start()
self.__depthImageData = None
self.__rgbImageData = None
#Determine viewport ranges for depth and setup renderer.
xMinDepth = 0.0
xMaxDepth = 0.5 if displayRGB else 1.0
yMin = 0.0
yMax = 1.0
self.__setupRenderer(xMinDepth, yMin, xMaxDepth, yMax)
#Determine viewport ranges for rgb and setup renderer.
if self.__displayRGB:
xMinRGB = xMaxDepth
xMaxRGB = 2.0 * xMinRGB
self.__setupRenderer(xMinRGB, yMin, xMaxRGB, yMax)
def __setupRenderer(self, xMin, yMin, xMax, yMax):
#Setup renderer.
self.__renderers.append(vtk.vtkRenderer())
idx = len(self.__renderers) - 1
self.__renderWindow.AddRenderer(self.__renderers[idx])
self.__renderers[idx].SetViewport(xMin, yMin, xMax, yMax)
self.__actors.append(vtk.vtkImageActor())
self.__renderers[idx].AddActor(self.__actors[idx])
self.__renderers[idx].ResetCamera()
def start(self):
self.__depthImageData is None or (self.__rgbImageData is None and self.__displayRGB):
return None
if self.__started:
return
self.__renderWindowInteractor.Initialize()
self.__renderWindow.Render()
self.__renderWindowInteractor.Start()
self.__started = True
def stop(self):
if not self.__started:
return
self.__renderWindowInteractor.Stop()
self.__renderWindow.Finalize()
self.__renderWindowInteractor.TerminateApp()
self.__started = False
def updateFrames(self, depthFrame, rgbFrame=None):
#Build vtkImageData here from the given numpy uint8_t arrays.
pass
编辑:我意识到我可以像演示的那样手动复制数据 here ,这对于 Cython 来说不会太不好(假设我能够在 Cython 中使用 vtkImageData
),但是最好直接使用 numpy 数组。
最佳答案
稍微更完整的答案(概括为 1-3 个 channel ,不同的数据类型)。
import vtk
import numpy as np
from vtk.util import numpy_support
def numpy_array_as_vtk_image_data(source_numpy_array):
"""
:param source_numpy_array: source array with 2-3 dimensions. If used, the third dimension represents the channel count.
Note: Channels are flipped, i.e. source is assumed to be BGR instead of RGB (which works if you're using cv2.imread function to read three-channel images)
Note: Assumes array value at [0,0] represents the upper-left pixel.
:type source_numpy_array: np.ndarray
:return: vtk-compatible image, if conversion is successful. Raises exception otherwise
:rtype vtk.vtkImageData
"""
if len(source_numpy_array.shape) > 2:
channel_count = source_numpy_array.shape[2]
else:
channel_count = 1
output_vtk_image = vtk.vtkImageData()
output_vtk_image.SetDimensions(source_numpy_array.shape[1], source_numpy_array.shape[0], channel_count)
vtk_type_by_numpy_type = {
np.uint8: vtk.VTK_UNSIGNED_CHAR,
np.uint16: vtk.VTK_UNSIGNED_SHORT,
np.uint32: vtk.VTK_UNSIGNED_INT,
np.uint64: vtk.VTK_UNSIGNED_LONG if vtk.VTK_SIZEOF_LONG == 64 else vtk.VTK_UNSIGNED_LONG_LONG,
np.int8: vtk.VTK_CHAR,
np.int16: vtk.VTK_SHORT,
np.int32: vtk.VTK_INT,
np.int64: vtk.VTK_LONG if vtk.VTK_SIZEOF_LONG == 64 else vtk.VTK_LONG_LONG,
np.float32: vtk.VTK_FLOAT,
np.float64: vtk.VTK_DOUBLE
}
vtk_datatype = vtk_type_by_numpy_type[source_numpy_array.dtype.type]
source_numpy_array = np.flipud(source_numpy_array)
# Note: don't flip (take out next two lines) if input is RGB.
# Likewise, BGRA->RGBA would require a different reordering here.
if channel_count > 1:
source_numpy_array = np.flip(source_numpy_array, 2)
depth_array = numpy_support.numpy_to_vtk(source_numpy_array.ravel(), deep=True, array_type = vtk_datatype)
depth_array.SetNumberOfComponents(channel_count)
output_vtk_image.SetSpacing([1, 1, 1])
output_vtk_image.SetOrigin([-1, -1, -1])
output_vtk_image.GetPointData().SetScalars(depth_array)
output_vtk_image.Modified()
return output_vtk_image
关于python - Numpy uint8_t 数组到 vtkImageData,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/45395269/