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image.getslice - Function

1.1.1 Get 1-D slice from the image


Description

This function returns a 1-D slice (the pixels and opionally the pixel mask) from the image file. The slice is constrained to lie in a plane of two cardinal axes (e.g. XY or YZ). At some point this constraint will be relaxed. A range of interpolation schemes are available.

You specify the slice as a polyline giving the x (x) and y (y) coordinates and the axes of the plane holding that slice (axes). As well, you must specify the absolute pixel coordinates of the other axes (coord). This defaults to the first pixel (e.g. first plane).

The return value is a record with fields ’pixels’ (interpolated intensity), ’mask’ (interpolated mask), ’xpos’ (x-location in absolute pixel coordinates), ’ypos’ (y-location in absolute pixel coordinates), ’distance’ (distance along slice in pixels), ’axes’ (the x and y axes of slice).

Arguments





Inputs

x

Polyline x vertices in absolute pixel coordinates

allowed:

doubleArray

Default:

y

Polyline y vertices in absolute pixel coordinates

allowed:

doubleArray

Default:

axes

Pixel axes of plane holding slice. Default is first two axes.

allowed:

intArray

Default:

01

coord

Specify pixel coordinate for other axes. Default is first pixel.

allowed:

intArray

Default:

-1

npts

Number of points in slice. Default is auto determination.

allowed:

int

Default:

0

method

The interpolation method, String from ’nearest’, ’linear’, ’cubic’

allowed:

string

Default:

linear

Returns
record

Example

 
Suppose that we have a 2-dimensional image. Then:  
 
"""  
#  
print "\t----\t getslice Ex 1 \t----"  
ia.maketestimage();  
rec = ia.getslice (x=[1,20], y=[2,30])     # SLice from [1,2] -> [20,30]  
print rec.keys()  
#[’distance’, ’xpos’, ’axes’, ’mask’, ’ypos’, ’pixel’]  
rec = ia.getslice (x=[1,20,25,11], y=[2,30,32,40]) # Polyline slice  
ia.close()  
#  
"""  
 

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