Practical overview
When it fits
Use Detecto when a Python workflow needs object detection with PyTorch, especially when training on a custom labeled dataset or processing image and video inputs.
Who it is for
- Python developers building object-detection workflows
- Practitioners training detectors for custom object classes
- Developers who need image or video inference and prediction visualization
Documented uses
- Train a detector using images labeled for custom classes.
- Run object detection on still images, videos or a live webcam.
- Inspect predictions as labels, bounding boxes and scores.
- Save trained model weights for later use.
Requirements & limits
The project documents installation with pip and specifies the MIT license.
- Detecto is a Python library, so its documented workflows involve code and local data paths rather than a hosted interface.
- The project builds on PyTorch and exposes its underlying torchvision model for additional control.
- The README shows both a brief pretrained video-inference example and more configurable training workflows using transforms, validation data and model selection.
Check current requirements in the official documentation. Source-based guidance does not mean OpenViST has run or independently tested this project.
Install Detecto and run video inference
Install the package and apply a pretrained object-detection model to an input video.
Before you start
- Python environment with pip
- Input video file
Steps
Install Detecto with the command below.
pip3 install detectoImport
Modelfromdetecto.coreanddetect_videofromdetecto.visualize.Initialize
model = Model()to load the documented pretrained model.Call
detect_video(model, 'input_video.mp4', 'output.avi')with the input and output paths.
Expected outcome
The example runs object detection on the input video and writes an output video file.
Guide limitations
- The example uses the pretrained Faster R-CNN ResNet-50 FPN model; custom classes require a training workflow.
- The project says pip should install dependencies automatically, but lists requirements.txt as a manual dependency reference if an issue occurs.
Train a detector on a labeled custom dataset
Load labeled images, train a model for chosen object classes and save the trained weights.
Before you start
- Detecto installed in a Python environment
- Custom image dataset with image and label data
- Object class names for the labels
Steps
Load the dataset with
Dataset('custom_dataset/').Initialize
Modelwith the target class names, such asModel(['dog', 'cat', 'rabbit']).Train the model by calling
model.fit(dataset).Save trained weights to a file with
model.save('model_weights.pth').
Expected outcome
A trained object-detection model with weights saved to a file.
Guide limitations
- The simple example assumes the custom dataset folder contains image and label data in a format Detecto can load.
- The advanced example documents additional dataset, transform and training options, but this recipe does not configure them.
Sources & review
Source record details
- Source availability
- Active
- Sources checked
- 15 October 2026
- Original website title
- alankbi/detecto · Official homepage title · retained in its source language

