readRegion

R2026b

Class: ImageAdapter

(Not recommended) Read region of image

The readRegion method of the ImageAdapter class is not recommended. Instead of ImageAdapter, use a blockedImage object. For more information, see Version History.

Syntax

data = readRegion(adapter,region_start, region_size)


Description

data = readRegion(adapter,region_start, region_size) reads an image region of size region_size with top-left pixel at coordinate region_start.

Input Arguments

adapter — Image adapter

ImageAdapter

Image adapter, specified as an instance of an ImageAdapter.

region_start — Top-left coordinates of region

2-element vector of positive integers

Top-left coordinates of the region to read, specified as a 2-element vector of positive integers of the form [row column].

region_size — Size of region

2-element vector of positive integers

Size of the region to read, specified as a 2-element vector of positive integers of the form [numrows numcolumns].

Output Arguments

data — Image data

numeric array

Image data, returned as a numeric array of size region_size.

Attributes

Abstract

true

To learn about attributes of methods, see Method Attributes.

Tips

• When you construct a class that inherits from the ImageAdapter class, you must implement this method.

Version History

Introduced in R2010a

R2026b: ImageAdapter.readRegion is not recommended

The readRegion method of the ImageAdapter class is not recommended. Instead, use a blockedImage object. The blockedImage object provides several advantages, including built-in adapters for common image formats. For unsupported formats, create a custom adapter by subclassing images.blocked.Adapter.

If your image format is supported by blockedImage, update your code by using the getRegion or getBlock functions of blockedImage. For unsupported image formats, use the getIOBlock function of images.blocked.Adapter.