| Parameter |
Parameter Description |
Parameter Type |
Options |
Default Value |
input |
The data to be predicted, supporting multiple input types (required). |
Python Var|str|list |
- Python Var: Image data represented by
numpy.ndarray.
- str: Local path of an image file or PDF file, such as
/root/data/img.jpg; URL link, such as the network URL of an image file or PDF file: example; Local directory, which must contain images to be predicted, such as the local path: /root/data/ (currently, prediction of PDF files in directories is not supported; PDF files must be specified with an exact file path).
- List: The elements of the list must be of the above types, such as
[numpy.ndarray, numpy.ndarray], ["/root/data/img1.jpg", "/root/data/img2.jpg"], ["/root/data1", "/root/data2"].
|
None |
thresholds |
The thresholds used during model inference. |
dict[str, float] |
- dict[str, float]: The key is a string representing the threshold name, and the value is a floating-point number between 0 and 1, representing the threshold value. For example, for GroundingDINO, the setting is
{"text_threshold": 0.25, "box_threshold": 0.3}, which means the text threshold for GroundingDINO is set to 0.25, and the object detection box threshold is set to 0.3.
|
None |
prompt |
The prompt used during model inference. |
str |
- str: This must be set according to the specific model. For example, for GroundingDINO, the prompt is
"{category1} . {category2} . {category3} .".
|
None |
(3) Process the prediction results. The prediction result for each sample is of the `dict` type and supports operations such as printing, saving as an image, and saving as a `json` file:
| Method |
Description |
Parameter |
Parameter Type |
Parameter Description |
Default Value |
print() |
Print the result to the terminal |
format_json |
bool |
Whether to format the output content using JSON indentation |
True |
indent |
int |
Specify the indentation level to beautify the output JSON data, making it more readable. Effective only when format_json is True |
4 |
ensure_ascii |
bool |
Control whether to escape non-ASCII characters to Unicode. When set to True, all non-ASCII characters will be escaped; False will retain the original characters. Effective only when format_json is True |
False |
save_to_json() |
Save the result as a JSON file |
save_path |
str |
Path to save the file. When it is a directory, the saved file name is consistent with the input file type naming |
None |
indent |
int |
Specify the indentation level to beautify the output JSON data, making it more readable. Effective only when format_json is True |
4 |
ensure_ascii |
bool |
Control whether to escape non-ASCII characters to Unicode. When set to True, all non-ASCII characters will be escaped; False will retain the original characters. Effective only when format_json is True |
False |
save_to_img() |
Save the result as an image file |
save_path |
str |
Path to save the file, supports directory or file path |
None |
- Calling the `print()` method will print the result to the terminal, with the printed content explained as follows:
- `input_path`: `(str)` The input path of the image to be predicted
- `page_index`: `(Union[int, None])` If the input is a PDF file, it indicates which page of the PDF it is, otherwise it is `None`
- `boxes`: `(list)` Detection box information, each element is a dictionary containing the following fields
- `label`: `(str)` Category name
- `score`: `(float)` Confidence score
- `coordinates`: `(list)` Detection box coordinates, in the format `[xmin, ymin, xmax, ymax]`
- Calling the `save_to_json()` method will save the above content to the specified `save_path`. If specified as a directory, the saved path will be `save_path/{your_img_basename}_res.json`; if specified as a file, it will be saved directly to that file. Since JSON files do not support saving numpy arrays, the `numpy.array` types will be converted to lists.
- Calling the `save_to_img()` method will save the visualization results to the specified `save_path`. If specified as a directory, the saved path will be `save_path/{your_img_basename}_res.{your_img_extension}`; if specified as a file, it will be saved directly to that file.
* Additionally, it also supports obtaining visualized images and prediction results through attributes, as follows:
API Reference
For the main operations provided by the service:
- The HTTP request method is POST.
- Both the request body and response body are JSON data (JSON objects).
- When the request is processed successfully, the response status code is
200, and the response body has the following attributes:
| Name |
Type |
Meaning |
logId |
string |
The UUID of the request. |
errorCode |
integer |
Error code. Fixed at 0. |
errorMsg |
string |
Error description. Fixed at "Success". |
result |
object |
Operation result. |
- When the request is not processed successfully, the response body has the following attributes:
| Name |
Type |
Meaning |
logId |
string |
The UUID of the request. |
errorCode |
integer |
Error code. Same as the response status code. |
errorMsg |
string |
Error description. |
The main operations provided by the service are as follows:
Perform object detection on an image.
POST /open-vocabulary-detection
- The attributes of the request body are as follows:
| Name |
Type |
Meaning |
Required |
image |
string |
The URL of the image file accessible by the server or the Base64 encoded result of the image file content. |
Yes |
prompt |
string |
The text prompt used for prediction. |
Yes |
thresholds |
object | null |
The thresholds used by the model for prediction. |
No |
- When the request is processed successfully, the
result in the response body has the following attributes:
| Name |
Type |
Meaning |
detectedObjects |
array |
Information about the position, category, etc., of the objects. |
image |
string |
The result image of object detection. The image is in JPEG format and encoded in Base64. |
Each element in detectedObjects is an object with the following attributes:
| Name |
Type |
Meaning |
bbox |
array |
The position of the object. The elements in the array are the x-coordinate of the top-left corner, the y-coordinate of the top-left corner, the x-coordinate of the bottom-right corner, and the y-coordinate of the bottom-right corner, in that order. |
categoryName |
string |
The name of the object category. |
score |
number |
The score of the object. |
An example of result is as follows:
{
"detectedObjects": [
{
"bbox": [
404.4967956542969,
90.15770721435547,
506.2465515136719,
285.4187316894531
],
"categoryName": "bird",
"score": 0.7418514490127563
},
{
"bbox": [
155.33145141601562,
81.10954284667969,
199.71136474609375,
167.4235382080078
],
"categoryName": "dog",
"score": 0.7328268885612488
}
],
"image": "xxxxxx"
}
Multi-language Service Call Examples
Python
import base64
import requests
API_URL = "http://localhost:8080/open-vocabulary-detection" # Service URL
image_path = "./open_vocabulary_detection.jpg"
output_image_path = "./out.jpg"
# Base64 encode the local image
with open(image_path, "rb") as file:
image_bytes = file.read()
image_data = base64.b64encode(image_bytes).decode("ascii")
payload = {"image": image_data, "prompt": "walking man . bus ."} # Base64 encoded file content or image URL
# Call the API
response = requests.post(API_URL, json=payload)
# Handle the response data
assert response.status_code == 200, f"{response.status_code}"
result = response.json()["result"]
with open(output_image_path, "wb") as file:
file.write(base64.b64decode(result["image"]))
print(f"Output image saved at {output_image_path}")
print("\nDetected objects:")
print(result["detectedObjects"])
C++
#include <iostream>
#include "cpp-httplib/httplib.h" // https://github.com/Huiyicc/cpp-httplib
#include "nlohmann/json.hpp" // https://github.com/nlohmann/json
#include "base64.hpp" // https://github.com/tobiaslocker/base64
int main() {
httplib::Client client("localhost:8080");
const std::string imagePath = "./demo.jpg";
const std::string outputImagePath = "./out.jpg";
httplib::Headers headers = {
{"Content-Type", "application/json"}
};
// Base64 encode the local image
std::ifstream file(imagePath, std::ios::binary | std::ios::ate);
std::streamsize size = file.tellg();
file.seekg(0, std::ios::beg);
std::vector<char> buffer(size);
if (!file.read(buffer.data(), size)) {
std::cerr << "Error reading file." << std::endl;
return 1;
}
std::string bufferStr(reinterpret_cast<const char*>(buffer.data()), buffer.size());
std::string encodedImage = base64::to_base64(bufferStr);
nlohmann::json jsonObj;
jsonObj["image"] = encodedImage;
std::string body = jsonObj.dump();
// Call the API
auto response = client.Post("/small-object-detection", headers, body, "application/json");
// Handle the response data
if (response && response->status == 200) {
nlohmann::json jsonResponse = nlohmann::json::parse(response->body);
auto result = jsonResponse["result"];
encodedImage = result["image"];
std::string decodedString = base64::from_base64(encodedImage);
std::vector<unsigned char> decodedImage(decodedString.begin(), decodedString.end());
std::ofstream outputImage(outPutImagePath, std::ios::binary | std::ios::out);
if (outputImage.is_open()) {
outputImage.write(reinterpret_cast<char*>(decodedImage.data()), decodedImage.size());
outputImage.close();
std::cout << "Output image saved at " << outPutImagePath << std::endl;
} else {
std::cerr << "Unable to open file for writing: " << outPutImagePath << std::endl;
}
auto detectedObjects = result["detectedObjects"];
std::cout << "\nDetected objects:" << std::endl;
for (const auto& category : detectedObjects) {
std::cout << category << std::endl;
}
} else {
std::cout << "Failed to send HTTP request." << std::endl;
return 1;
}
return 0;
}
Java
import okhttp3.*;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.JsonNode;
import com.fasterxml.jackson.databind.node.ObjectNode;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.Base64;
public class Main {
public static void main(String[] args) throws IOException {
String API_URL = "http://localhost:8080/small-object-detection"; // Service URL
String imagePath = "./demo.jpg"; // Local image path
String outputImagePath = "./out.jpg"; // Output image path
// Encode the local image in Base64
File file = new File(imagePath);
byte[] fileContent = java.nio.file.Files.readAllBytes(file.toPath());
String imageData = Base64.getEncoder().encodeToString(fileContent);
ObjectMapper objectMapper = new ObjectMapper();
ObjectNode params = objectMapper.createObjectNode();
params.put("image", imageData); // Base64-encoded file content or image URL
// Create an OkHttpClient instance
OkHttpClient client = new OkHttpClient();
MediaType JSON = MediaType.Companion.get("application/json; charset=utf-8");
RequestBody body = RequestBody.Companion.create(params.toString(), JSON);
Request request = new Request.Builder()
.url(API_URL)
.post(body)
.build();
// Call the API and process the response data
try (Response response = client.newCall(request).execute()) {
if (response.isSuccessful()) {
String responseBody = response.body().string();
JsonNode resultNode = objectMapper.readTree(responseBody);
JsonNode result = resultNode.get("result");
String base64Image = result.get("image").asText();
JsonNode detectedObjects = result.get("detectedObjects");
byte[] imageBytes = Base64.getDecoder().decode(base64Image);
try (FileOutputStream fos = new FileOutputStream(outputImagePath)) {
fos.write(imageBytes);
}
System.out.println("Output image saved at " + outputImagePath);
System.out.println("\nDetected objects: " + detectedObjects.toString());
} else {
System.err.println("Request failed with code: " + response.code());
}
}
}
}
Go
package main
import (
"bytes"
"encoding/base64"
"encoding/json"
"fmt"
"io/ioutil"
"net/http"
)
func main() {
API_URL := "http://localhost:8080/small-object-detection"
imagePath := "./demo.jpg"
outputImagePath := "./out.jpg"
// Encode the local image in Base64
imageBytes, err := ioutil.ReadFile(imagePath)
if err != nil {
fmt.Println("Error reading image file:", err)
return
}
imageData := base64.StdEncoding.EncodeToString(imageBytes)
payload := map[string]string{"image": imageData} // Base64-encoded file content or image URL
payloadBytes, err := json.Marshal(payload)
if err != nil {
fmt.Println("Error marshaling payload:", err)
return
}
// Call the API
client := &http.Client{}
req, err := http.NewRequest("POST", API_URL, bytes.NewBuffer(payloadBytes))
if err != nil {
fmt.Println("Error creating request:", err)
return
}
res, err := client.Do(req)
if err != nil {
fmt.Println("Error sending request:", err)
return
}
defer res.Body.Close()
// Process the response data
body, err := ioutil.ReadAll(res.Body)
if err != nil {
fmt.Println("Error reading response body:", err)
return
}
type Response struct {
Result struct {
Image string `json:"image"`
DetectedObjects []map[string]interface{} `json:"detectedObjects"`
} `json:"result"`
}
var respData Response
err = json.Unmarshal([]byte(string(body)), &respData)
if err != nil {
fmt.Println("Error unmarshaling response body:", err)
return
}
outputImageData, err := base64.StdEncoding.DecodeString(respData.Result.Image)
if err != nil {
fmt.Println("Error decoding base64 image data:", err)
return
}
err = ioutil.WriteFile(outputImagePath, outputImageData, 0644)
if err != nil {
fmt.Println("Error writing image to file:", err)
return
}
fmt.Printf("Image saved at %s.jpg\n", outputImagePath)
fmt.Println("\nDetected objects:")
for _, category := range respData.Result.DetectedObjects {
fmt.Println(category)
}
}
C#
using System;
using System.IO;
using System.Net.Http;
using System.Net.Http.Headers;
using System.Text;
using System.Threading.Tasks;
using Newtonsoft.Json.Linq;
class Program
{
static readonly string API_URL = "http://localhost:8080/small-object-detection";
static readonly string imagePath = "./demo.jpg";
static readonly string outputImagePath = "./out.jpg";
static async Task Main(string[] args)
{
var httpClient = new HttpClient();
// Base64 encode the local image
byte[] imageBytes = File.ReadAllBytes(imagePath);
string image_data = Convert.ToBase64String(imageBytes);
var payload = new JObject{ { "image", image_data } }; // Base64 encoded file content or image URL
var content = new StringContent(payload.ToString(), Encoding.UTF8, "application/json");
// Call the API
HttpResponseMessage response = await httpClient.PostAsync(API_URL, content);
response.EnsureSuccessStatusCode();
// Process the API response
string responseBody = await response.Content.ReadAsStringAsync();
JObject jsonResponse = JObject.Parse(responseBody);
string base64Image = jsonResponse["result"]["image"].ToString();
byte[] outputImageBytes = Convert.FromBase64String(base64Image);
File.WriteAllBytes(outputImagePath, outputImageBytes);
Console.WriteLine($"Output image saved at {outputImagePath}");
Console.WriteLine("\nDetected objects:");
Console.WriteLine(jsonResponse["result"]["detectedObjects"].ToString());
}
}
Node.js
const axios = require('axios');
const fs = require('fs');
const API_URL = 'http://localhost:8080/small-object-detection'
const imagePath = './demo.jpg'
const outputImagePath = "./out.jpg";
let config = {
method: 'POST',
maxBodyLength: Infinity,
url: API_URL,
data: JSON.stringify({
'image': encodeImageToBase64(imagePath) // Base64 encoded file content or image URL
})
};
// Base64 encode the local image
function encodeImageToBase64(filePath) {
const bitmap = fs.readFileSync(filePath);
return Buffer.from(bitmap).toString('base64');
}
// Call the API
axios.request(config)
.then((response) => {
// Process the API response
const result = response.data["result"];
const imageBuffer = Buffer.from(result["image"], 'base64');
fs.writeFile(outputImagePath, imageBuffer, (err) => {
if (err) throw err;
console.log(`Output image saved at ${outputImagePath}`);
});
console.log("\nDetected objects:");
console.log(result["detectedObjects"]);
})
.catch((error) => {
console.log(error);
});
PHP
<?php
$API_URL = "http://localhost:8080/small-object-detection"; // Service URL
$image_path = "./demo.jpg";
$output_image_path = "./out.jpg";
// Base64 encode the local image
$image_data = base64_encode(file_get_contents($image_path));
$payload = array("image" => $image_data); // Base64 encoded file content or image URL
// Call the API
$ch = curl_init($API_URL);
curl_setopt($ch, CURLOPT_POST, true);
curl_setopt($ch, CURLOPT_POSTFIELDS, json_encode($payload));
curl_setopt($ch, CURLOPT_HTTPHEADER, array('Content-Type: application/json'));
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
$response = curl_exec($ch);
curl_close($ch);
// Process the API response
$result = json_decode($response, true)["result"];
file_put_contents($output_image_path, base64_decode($result["image"]));
echo "Output image saved at " . $output_image_path . "\n";
echo "\nDetected objects:\n";
print_r($result["detectedObjects"]);
?>
The general open vocabulary detection pipeline includes an open vocabulary detection module. You can choose the model based on the benchmark data below.
If you prioritize model accuracy, choose a model with higher accuracy; if you prioritize inference speed, choose a model with faster inference speed; if you prioritize storage size, choose a model with a smaller storage size.
