Upload an Annotation

If you already have existing annotations, along with your images, you can upload them to Roboflow.

This works with any of our supported annotation formats that use an annotation file that references the file name of the uploaded image.

Did you know? You can drag and drop (or select) the annotation files along with your images on the Upload page of the app without using the API.

Python SDK

You can attach annotation files when you upload images via the Python SDK. See more in the Python SDK reference

Example: Uploading a Local Annotation

import glob
from roboflow import Roboflow

# Initialize Roboflow client
rf = Roboflow(api_key="YOUR_PRIVATE_API_KEY")

# Directory path and file extension for images
dir_name = "PATH/TO/IMAGES"
file_extension_type = ".jpg"

# Annotation file path and format (e.g., .coco.json)
annotation_filename = "PATH/TO/_annotations.coco.json"

# Get the upload project from Roboflow workspace
project = rf.workspace().project("YOUR_PROJECT_NAME")

# Upload images
image_glob = glob.glob(dir_name + '/*' + file_extension_type)
for image_path in image_glob:
    print(project.single_upload(
        image_path=image_path,
        annotation_path=annotation_filename,
        # -- optional parameters: --
        # annotation_labelmap=labelmap_path,
        # split='train',
        # num_retry_uploads=0,
        # batch_name='batch_name',
        # tag_names=['tag1', 'tag2'],
        # is_prediction=False,
    ))

cURL

Example

Attaching a VOC XML annotation to an image with ID abc123 in the your-dataset dataset called YOUR_ANNOTATION.xml:

cat YOUR_ANNOTATION.xml | curl -d @- \
"https://api.roboflow.com/dataset/your-dataset/annotate/abc123?\
api_key=YOUR_KEY&\
name=YOUR_ANNOTATION.xml"

Attaching a Darknet TXT annotation to an image with ID abc123 in the your-dataset dataset called YOUR_ANNOTATION.txt using a json labelmap - in this case we need to send the contents of the annotation file in a json instead of just sending it as the body.

#!/bin/bash
# store the annotation as a json-compatible string
txt_content=$(cat YOUR_ANNOTATION.txt | sed 's/\\/\\\\/g; s/"/\\"/g; s/$/\\n/' | tr -d '\n')
# create a json string with the annotation file and the label map [0=flower, 1=leaf]
json_payload="{ \"annotationFile\": \"$txt_content\", \"labelmap\":{\"0\":\"flower\", \"1\":\"leaf\"} }"

# upload the annotation + labelmap
echo $json_payload | curl -H "Content-Type: application/json" -d @- \
"https://api.roboflow.com/dataset/cultura-pepino-dark/annotate/abc123?\
api_key=YOUR_KEY&\
name=YOUR_ANNOTATION.txt"

JavaScript

We're using axios to perform the POST request in this example so first run npm install axios to install the dependency.

Uploading a Local Image

const axios = require("axios");
const fs = require("fs");

const filename = "YOUR_ANNOTATION.xml";
const annotation = fs.readFileSync(filename, "utf-8");

axios({
    method: "POST",
    url: "https://api.roboflow.com/dataset/your-dataset/annotate/abc123",
    params: {
        api_key: "YOUR_KEY",
        name: filename
    },
    data: annotation,
    headers: {
        "Content-Type": "text/plain"
    }
})
.then(function(response) {
    console.log(response.data);
})
.catch(function(error) {
    console.log(error.message);
});

Android and Java

Kotlin

Uploading with base64 encoded image:

import java.io.*
import java.net.HttpURLConnection
import java.net.URL
import java.nio.charset.StandardCharsets
import java.util.*

fun main() {
    // Get Image Path
    val filePath = System.getProperty("user.dir") + System.getProperty("file.separator") + "YOUR_IMAGE.jpg"
    val file = File(filePath)

    // Base 64 Encode
    val encodedFile: String
    val fileInputStreamReader = FileInputStream(file)
    val bytes = ByteArray(file.length().toInt())
    fileInputStreamReader.read(bytes)
    encodedFile = String(Base64.getEncoder().encode(bytes), StandardCharsets.US_ASCII)
    val API_KEY = "" // Your API Key
    val DATASET_NAME = "your-dataset" // Set Dataset Name (Found in Dataset URL)

    // Construct the URL
    val uploadURL = "https://api.roboflow.com/dataset/" +
            DATASET_NAME + "/upload" +
            "?api_key=" + API_KEY +
            "&name=YOUR_IMAGE.jpg" +
            "&split=train"

    // Http Request
    var connection: HttpURLConnection? = null
    try {
        // Configure connection to URL
        val url = URL(uploadURL)
        connection = url.openConnection() as HttpURLConnection
        connection.requestMethod = "POST"
        connection.setRequestProperty("Content-Type",
                "application/x-www-form-urlencoded")
        connection.setRequestProperty("Content-Length",
                Integer.toString(encodedFile.toByteArray().size))
        connection.setRequestProperty("Content-Language", "en-US")
        connection.useCaches = false
        connection.doOutput = true

        //Send request
        val wr = DataOutputStream(
                connection.outputStream)
        wr.writeBytes(encodedFile)
        wr.close()

        // Get Response
        val stream = connection.inputStream
        val reader = BufferedReader(InputStreamReader(stream))
        var line: String?
        while (reader.readLine().also { line = it } != null) {
            println(line)
        }
        reader.close()
    } catch (e: Exception) {
        e.printStackTrace()
    } finally {
        connection?.disconnect()
    }
}
main()

Adding an Image Hosted Elsewhere via URL:

import java.io.BufferedReader
import java.io.DataOutputStream
import java.io.InputStreamReader
import java.net.HttpURLConnection
import java.net.URL
import java.net.URLEncoder
import java.nio.charset.StandardCharsets

fun main() {
    val imageURL = "https://i.imgur.com/PEEvqPN.png" // Replace Image URL
    val API_KEY = "" // Your API Key
    val DATASET_NAME = "your-dataset" // Set Dataset Name (Found in Dataset URL)

    // Upload URL
    val uploadURL = ("https://api.roboflow.com/dataset/" + DATASET_NAME + "/upload" + "?api_key=" + API_KEY
            + "&name=YOUR_IMAGE.jpg" + "&split=train" + "&image="
            + URLEncoder.encode(imageURL, "utf-8"))

    // Http Request
    var connection: HttpURLConnection? = null
    try {
        // Configure connection to URL
        val url = URL(uploadURL)
        connection = url.openConnection() as HttpURLConnection
        connection.requestMethod = "POST"
        connection.setRequestProperty("Content-Type", "application/x-www-form-urlencoded")
        connection.setRequestProperty("Content-Length", Integer.toString(uploadURL.toByteArray().size))
        connection.setRequestProperty("Content-Language", "en-US")
        connection.useCaches = false
        connection.doOutput = true

        // Send request
        val wr = DataOutputStream(connection.outputStream)
        wr.writeBytes(uploadURL)
        wr.close()

        // Get Response
        val stream = connection.inputStream
        val reader = BufferedReader(InputStreamReader(stream))
        var line: String?
        while (reader.readLine().also { line = it } != null) {
            println(line)
        }
        reader.close()
    } catch (e: Exception) {
        e.printStackTrace()
    } finally {
        connection?.disconnect()
    }
}

main()

Android (Java)

Uploading with base64 encoded image:

import java.io.*;
import java.net.HttpURLConnection;
import java.net.URL;
import java.nio.charset.StandardCharsets;
import java.util.Base64;

public class UploadLocal {
    public static void main(String[] args) throws IOException {
        // Get Image Path
        String filePath = System.getProperty("user.dir") + System.getProperty("file.separator") + "YOUR_IMAGE.jpg";
        File file = new File(filePath);

        // Base 64 Encode
        String encodedFile;
        FileInputStream fileInputStreamReader = new FileInputStream(file);
        byte[] bytes = new byte[(int) file.length()];
        fileInputStreamReader.read(bytes);
        encodedFile = new String(Base64.getEncoder().encode(bytes), StandardCharsets.US_ASCII);

        String API_KEY = ""; // Your API Key
        String DATASET_NAME = "your-dataset"; // Set Dataset Name (Found in Dataset URL)

        // Construct the URL
        String uploadURL =
                "https://api.roboflow.com/dataset/"+
                        DATASET_NAME + "/upload" +
                        "?api_key=" + API_KEY +
                        "&name=YOUR_IMAGE.jpg" +
                        "&split=train";

        // Http Request
        HttpURLConnection connection = null;
        try {
            //Configure connection to URL
            URL url = new URL(uploadURL);
            connection = (HttpURLConnection) url.openConnection();
            connection.setRequestMethod("POST");
            connection.setRequestProperty("Content-Type",
                    "application/x-www-form-urlencoded");

            connection.setRequestProperty("Content-Length",
                    Integer.toString(encodedFile.getBytes().length));
            connection.setRequestProperty("Content-Language", "en-US");
            connection.setUseCaches(false);
            connection.setDoOutput(true);

            //Send request
            DataOutputStream wr = new DataOutputStream(
                    connection.getOutputStream());
            wr.writeBytes(encodedFile);
            wr.close();

            // Get Response
            InputStream stream = connection.getInputStream();
            BufferedReader reader = new BufferedReader(new InputStreamReader(stream));
            String line;
            while ((line = reader.readLine()) != null) {
                System.out.println(line);
            }
            reader.close();
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            if (connection != null) {
                connection.disconnect();
            }
        }
    }
}

Adding an Image Hosted Elsewhere via URL:

import java.io.BufferedReader;
import java.io.DataOutputStream;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLEncoder;
import java.nio.charset.StandardCharsets;

public class UploadHosted {
    public static void main(String[] args) {
        String imageURL = "https://i.imgur.com/PEEvqPN.png"; // Replace Image URL
        String API_KEY = ""; // Your API Key
        String DATASET_NAME = "your-dataset"; // Set Dataset Name (Found in Dataset URL)

        // Upload URL
        String uploadURL = "https://api.roboflow.com/dataset/" + DATASET_NAME + "/upload" + "?api_key=" + API_KEY
                + "&name=YOUR_IMAGE.jpg" + "&split=train" + "&image="
                + URLEncoder.encode(imageURL, StandardCharsets.UTF_8);

        // Http Request
        HttpURLConnection connection = null;
        try {
            // Configure connection to URL
            URL url = new URL(uploadURL);
            connection = (HttpURLConnection) url.openConnection();
            connection.setRequestMethod("POST");
            connection.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");

            connection.setRequestProperty("Content-Length", Integer.toString(uploadURL.getBytes().length));
            connection.setRequestProperty("Content-Language", "en-US");
            connection.setUseCaches(false);
            connection.setDoOutput(true);

            // Send request
            DataOutputStream wr = new DataOutputStream(connection.getOutputStream());
            wr.writeBytes(uploadURL);
            wr.close();

            // Get Response
            InputStream stream = connection.getInputStream();
            BufferedReader reader = new BufferedReader(new InputStreamReader(stream));
            String line;
            while ((line = reader.readLine()) != null) {
                System.out.println(line);
            }
            reader.close();
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            if (connection != null) {
                connection.disconnect();
            }
        }
    }
}