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##### regionmanager.box - Function

1.1.2 Create a pixel box region

Description

This function creates a multi-dimensional pixel box region. The box is specified by a bottom-left corner, and top-right corner and an increment (or stride). Pixel coordinates are considered to run from 1 at the bottom left corner of the image to the image shape at the top-right corner of the image.

You can specify whether the coordinates are given as pixel coordinates (frac=F) or fractions of the image shape (frac=T). Absolute fractions are in the range [0,1].

You can also specify whether the coordinates are given as absolute coordinates (absrel=’abs’) or relative to the reference pixel (absrel=’relref’) or relative to the center of the image (absrel=’relcen’).

Arguments

 Inputs blc blc of the box allowed: doubleArray Default: 0 Unity trc trc of the box allowed: doubleArray Default: -1 Shape inc increment allowed: doubleArray Default: 1 absrel Absolute or relative coordinates allowed: string Default: relref relcen abs frac Pixel or fractional coordinates allowed: bool Default: false F comment A comment stored with the region allowed: string Default:
Returns
record

Example

ia.open(’myimage’)
ia.shape()
[155 178 256]

r = rg.box()                 # create region
-
- ia.boundingbox(r)
[blc=[1 1 1] , trc=[155 178 256] , inc=[1 1 1] , bbShape=[155 178 256] ,
regionShape=[155 178 256] , imageShape=[155 178 256] ]

This region, on application to an image, selects the entire image.

Example

- ia.open(’myimage’)
- ia.shape()
[155 178 256]
-
- r=rg.box(blc=[5,10])
- ia.boundingbox(r)
[blc=[5 10 1] , trc=[155 178 256] , inc=[1 1 1] , bbShape=[151 169 256] ,
regionShape=[151 169 256] , imageShape=[155 178 256] ]

This region is only specified for the first two axes of the blc.
Automatic extension rules apply for the other axis and the trc
(defaults to the shape).

Example

- ia.open(’myimage’)
- ia.shape()
[155 178 256]
-
- r = rg.box(blc=[10, 10, 10], trc=[20, 20, 20], inc=[2, 2, 2])
- ia.boundingbox(r)
[blc=[10 10 10] , trc=[20 20 20] , inc=[2 2 2] , bbShape=[11 11 11] ,
regionShape=[6 6 6] , imageShape=[155 178 256] ]
-
stats=ia.statistics(region=r, list=False);
stats[’npts’][0]
216

This region picks out every other pixel in the 3D box.  The
‘‘regionShape’’ field of the bounding box record does reflect the
increment whereas ‘‘bbShape’’ does not.  You can see that the number of
points used in determining the statistics (216) reflects the increment
as well.

Example

THIS EXAMPLE IS NOT VALID YET

- ia.open(’myimage’)
- ia.shape()
[64 128]
-
- rmd = rg.dflt()
- r = rg.box([-5,-10], [rmd,20], absrel=’relcen’)
-
- ia.boundingbox(r)
[blc=[28 55] , trc=[64 85] , inc=[1 1] , bbShape=[37 31] ,
regionShape=[37 31] , imageShape=[64 128] ]

The region is specified in pixels relative to the center of the image.
Note the use of the default value ({\cf rg.dflt()}) to default the first
axis of the trc argument to the image shape without having to know the
image shape.

Example

- ia.open(’myimage’)
- ia.shape()
[155 178 256]
-
- summ=ia.summary(list=False)
[90 90 1]
-
- r = rg.box([-0.25,-0.3], [0.25, 0.5], frac=True, absrel=’relref’)
- ia.boundingbox(r)
[blc=[39 37 1] , trc=[116 178 256] , inc=[1 1 1] , bbShape=[78 142 256] ,
regionShape=[78 142 256] , imageShape=[155 178 256] ]

This example shows selection by relative to reference pixel fractional
coordinates plus auto extension to unspecified axes.

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