Image Batch Processor

Apply function to multiple images

Description

The Image Batch Processor app enables you to process multiple images using the same function. Using this app, you can:

• Load images from a folder or from an imageDatastore object in the workspace.

• Process images using an existing MATLAB^® function, or create a custom batch processing function using a code template.

• View intermediate and final processed images.

• Export processed images to an output folder or the workspace.

• Generate a function to process additional images outside the app.

If you have Parallel Computing Toolbox™ you can process the images on a local parallel pool.

To get started, see Process Folder of Images Using Image Batch Processor App.

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Specify Batch Processing Function

You can specify the batch processing function as one of these options:

• Existing MATLAB function — Specify an existing built-in or user-created function on the MATLAB search path. Type the function name in the Function Name box, or select it from the list. Alternatively, click Open to navigate to the function file you want to use.

• Create new function — Create a custom batch processing function using a code template. Click Create in the app toolstrip to open the template.

A batch processing function can accept one or two input arguments.

• Image — The first input must be the image array im.

• Information structure — The optional second argument is a structure, info, that contains information about the input image file. The info argument is useful if your batch processing function internally calls one or more functions that require a filename as input, such as imread or rawinfo. For details, see Access File Information.

Open the Image Batch Processor App

• MATLAB Toolstrip: On the Apps tab, under Image Processing and Computer Vision, click the Image Batch Processor app icon.

• MATLAB command prompt: Enter imageBatchProcessor.

Examples

• Process Folder of Images Using Image Batch Processor App
• Process Images Using Image Batch Processor App with File Metadata

Programmatic Use

imageBatchProcessor

imageBatchProcessor opens the Image Batch Processor app, which enables you to process a folder of images.

imageBatchProcessor(folderLocation)

imageBatchProcessor(folderLocation) opens the app and loads the batch of images stored in the folder folderLocation. (since R2023a)

imageBatchProcessor(imds)

imageBatchProcessor(imds) opens the app and loads the images in the imageDatastore object imds. (since R2023a)

imageBatchProcessor close

imageBatchProcessor close closes all open instances of the Image Batch Processor app.

More About

Access File Information

Access file information within your batch processing function by including the optional info input argument. To pass the info input argument to your batch processing function, select Include Image Info in the app toolstrip before you process any images. If the batch processing function expects the info argument, you must select the Include Image Info check box or the app returns an error.

The app automatically creates info by using the datastore read object function, regardless of whether you load the images into the app from a folder or an imageDatastore object. The info structure contains these fields:

• Filename — The image source filename, including the path string, name of the file, and file extension.

• FileSize — Total file size, in bytes.

• Label — Image label name, if present. Otherwise, the Label field contains an empty string.

In the batch processing function code template, access the file information in info using dot notation. For example, use this code to access the input image filename.

filename = info.Filename

You can then use the filename to access additional file information. For example, use imread to read the colormap from an indexed image file, or read metadata using functions such as imfinfo, rawinfo, or dicominfo.

Version History

Introduced in R2015a

R2023a: Support for image datastores and other enhancements

The Image Batch Processor app includes several new capabilities:

• Image datastore support — Load a batch of images by importing an imageDatastore object from the MATLAB workspace.

• Support for additional file formats — load images from RAW file formats and EXR images.

• Additional command Line syntaxes — Open the Image Batch Processor and load images using two new syntaxes.

  This syntax opens the app and loads the batch of images stored in the folder folderLocation.

  imageBatchProcessor(folderLocation)

  This syntax opens the app and loads the images in the imageDatastore object imds.

  imageBatchProcessor(imds)

• You can now optionally pass a second input argument, info, to your batch processing function. The info argument contains information about the image source, including the image filename. For an example that uses the info argument, see Process Images Using Image Batch Processor App with File Metadata.