Image Category Classification and Image Retrieval

Create a bag of visual words for image classification and content-based image retrieval (CBIR) systems

To classify images into categories, you generate a histogram of visual word occurrences that represent an image. These histograms, called a bag of visual words, are used to train an image category classifier. You can also use the Computer Vision Toolbox™ functions to search by image, also known as a content-based image retrieval (CBIR) system. CBIR systems are used to retrieve images from a collection of images that are similar to a query image.

Apps

Image Labeler	Label images for computer vision applications
Video Labeler	Label video for computer vision applications

Functions

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Classification

`trainImageCategoryClassifier`	Train an image category classifier
`bagOfFeatures`	Bag of visual words object
`imageCategoryClassifier`	Predict image category
`invertedImageIndex`	Search index that maps visual words to images

Evaluation

`evaluateImageRetrieval`	Evaluate image search results
`indexImages`	Create image search index
`retrieveImages`	Search image set for similar image
`imageDatastore`	数据存储的图像数据

Topics

Get Started

Get Started with the Image Labeler

Interactively label rectangular ROIs for object detection, pixels for semantic segmentation, and scenes for image classification.

Classify Images

Create a Custom Feature Extractor

You can use the bag-of-features (BoF) framework with many different types of image features.

Image Classification with Bag of Visual Words

Use the Computer Vision Toolbox functions for image category classification by creating a bag of visual words.

Featured Examples

Image Retrieval Using Customized Bag of Features

Create a Content Based Image Retrieval (CBIR) system using a customized bag-of-features workflow.

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Image Category Classification Using Bag of Features

Use a bag of features approach for image category classification. This technique is also often referred to as bag of words. Visual image categorization is a process of assigning a category label to an image under test. Categories may contain images representing just about anything, for example, dogs, cats, trains, boats.

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