getRegion

Read arbitrary region of blocked image

Since R2021a

Syntax

pixels = getRegion(bim,pixelStart,pixelEnd)

pixels = getRegion(bim,pixelStart,pixelEnd,Level=L)

Description

pixels = getRegion(bim,pixelStart,pixelEnd) returns all the pixels in the blocked image bim, in the region specified by pixelStart and pixelEnd.

pixels = getRegion(bim,pixelStart,pixelEnd,Level=L) gets the specified region from the L'th resolution level of the multiresolution blockedImage object, bim. pixelStart and pixelEnd are pixel subscripts at the L'th resolution level.

Examples

Read Same Region from Multiple Levels

Create a blocked image.

bim = blockedImage("tumor_091R.tif");

Specify the start and end points of a region in the blocked image at resolution level 1, and retrieve the data.

pixelStartLevel1 = [2100 1800];
pixelEndLevel1 = [2600 2300];
imLevel1 = getRegion(bim,pixelStartLevel1,pixelEndLevel1,Level=1);

Convert the start and end points of the region from pixel subscripts to world coordinates.

worldStartLevel1 = sub2world(bim,pixelStartLevel1,Level=1);
worldEndLevel1 = sub2world(bim,pixelEndLevel1,Level=1);

Convert the start and end points of the region from world coordinates to pixel subscripts at resolution level 3, and retrieve the data.

pixelStartLevel3 = world2sub(bim,worldStartLevel1,Level=3);
pixelEndLevel3 = world2sub(bim, worldEndLevel1,Level=3);
imLevel3 = getRegion(bim,pixelStartLevel3,pixelEndLevel3,Level=3);

Display the region at both resolution levels.

montage({imLevel1,imLevel3});

Input Arguments

bim — Blocked image

blockedImage object

Blocked image, specified as a blockedImage object.

pixelStart — Starting pixel of region

1-by-N vector

Starting pixel of the region at the desired resolution level, specified as a 1-by-N vector of pixel subscripts in the form [row,column,...,subN]. N is equal to or less than the number of dimensions of the blocked image bim. If you specify pixel subscripts with a smaller dimensionality than the blocked image, then the getRegion function pads the remaining dimensions with the value 1.

pixelEnd — Ending pixel of region

1-by-N vector

Ending pixel of the region at the desired resolution level, specified as a 1-by-N vector of pixel subscripts in the form [row,column,...,subN]. N is equal to or less than the number of dimensions of the blocked image bim. If you specify pixel subscripts with a smaller dimensionality than the blocked image, then the getRegion function pads the remaining dimensions with the value 1.

L — Resolution level

1 (default) | positive integer

Resolution level, specified as a positive integer that is less than or equal to the number of resolution levels of bim.

Output Arguments

pixels — Pixels in specified region

numeric array

Pixels in specified region, returned as a numeric array.

Version History

Introduced in R2021a

R2023a: Support for lower dimensionality pixel subscripts

You can now specify the pixel subscripts in a lower dimensionality than the dimensionality of the blocked image bim. The function returns the world coordinates with the same dimensionality as the blocked image, with singleton dimensions for the unspecified dimensions.