--- comments: true --- # PaddleX Image Classification Task Module Data Annotation Tutorial This document will introduce how to use the [Labelme](https://github.com/wkentaro/labelme) annotation tool to complete data annotation for image classification related single models. Click on the above link to refer to the homepage documentation for installing the data annotation tool and viewing detailed usage procedures. ## 1. Labelme Annotation ### 1.1 Introduction to Labelme Annotation Tool `Labelme` is a Python-based image annotation software with a graphical interface. It can be used for tasks such as image classification, object detection, and image segmentation. In instance segmentation annotation tasks, labels are stored as `JSON` files. ### 1.2 Labelme Installation To avoid environment conflicts, it is recommended to install in a `conda` environment. ```bash conda create -n labelme python=3.10 conda activate labelme pip install pyqt5 pip install labelme ``` ### 1.3 Labelme Annotation Process #### 1.3.1 Prepare Data for Annotation * Create a root directory for the dataset, such as `pets`. * Create an `images` directory (must be named `images`) within `pets` and store the images to be annotated in the `images` directory, as shown below: * Create a category label file `flags.txt` for the dataset to be annotated in the `pets` folder, and write the categories of the dataset to be annotated into `flags.txt` line by line. Taking the `flags.txt` for a cat and dog classification dataset as an example, as shown below: #### 1.3.2 Start Labelme Navigate to the root directory of the dataset to be annotated in the terminal and start the `labelme` annotation tool. ```bash cd path/to/pets labelme images --nodata --autosave --output annotations --flags flags.txt ``` * `flags` creates classification labels for images, passing in the path to the labels. * `nodata` stops storing image data in JSON files. * `autosave` enables automatic saving. * `output` specifies the storage path for label files. #### 1.3.3 Start Image Annotation * After starting `labelme`, it will look like this: * Select the category in the `Flags` interface. * After annotation, click Save. (If `output` is not specified when starting `labelme`, it will prompt to select a save path upon the first save. If `autosave` is specified, there is no need to click the Save button). * Then click `Next Image` to annotate the next image. * After annotating all images, use the [convert_to_imagenet.py](https://paddle-model-ecology.bj.bcebos.com/paddlex/PaddleX3.0/doc_images/applications/image_classification_dataset_prepare/convert_to_imagenet.py) script to convert the annotated dataset to the `ImageNet-1k` dataset format, generating `train.txt`, `val.txt`, and `label.txt`. ```bash python convert_to_imagenet.py --dataset_path /path/to/dataset ``` `dataset_path` is the path to the annotated `labelme` format classification dataset. * The final directory structure after organization is as follows: ## 2. Data Format * The dataset defined by PaddleX for image classification tasks is named ClsDataset, with the following organizational structure and annotation format: ```bash dataset_dir # Root directory of the dataset, the directory name can be changed ├── images # Directory for saving images, the directory name can be changed, but note the correspondence with the content of train.txt and val.txt ├── label.txt # Correspondence between annotation IDs and category names, the file name cannot```bash classname1 classname2 classname3 ... ``` Modified `label.txt`: ```bash 0 classname1 1 classname2 2 classname3 ...