API Reference - JavaScript
The primary class of the library is DocumentNormalizer. The following code snippets shows the basic usage.
- Detect and normalize a still image
let normalizer = await Dynamsoft.DDN.DocumentNormalizer.createInstance();
let quads = await normalizer.detectQuad(imagePath);
let normalizedImageResult = await normalizer.normalize(imagePath, { quad: quads[0].location });
if(normalizedImageResult) {
// Show the normalized image in a Canvas
const cvs = normalizedImageResult.image.toCanvas();
document.querySelector("#normalized-result").appendChild(cvs);
}
// Download the normalized image
let img = await normalizedImageResult.saveToFile("example.png", true);
- Detect and normalize continuous video frames
(async function() {
cameraEnhancer = await Dynamsoft.DCE.CameraEnhancer.createInstance();
normalizer = await Dynamsoft.DDN.DocumentNormalizer.createInstance();
await normalizer.setImageSource(cameraEnhancer, { resultsHighlightBaseShapes: Dynamsoft.DCE.DrawingItem });
await document.getElementById('div-ui-container').append(cameraEnhancer.getUIElement());
// Triggered when a quadrilateral is detected from a video frame.
normalizer.onQuadDetected = (quadResults, sourceImage) => {
console.log(quadResults);
};
// Click the button to pause the video and edit a quadrilateral.
document.getElementById('confirmQuadForNormalization').addEventListener("click", () => {
normalizer.confirmQuadForNormalization();
});
// Click the button to normalize with the selected/adjusted quadrilateral.
document.getElementById('normalizeWithConfirmedQuad').addEventListener("click", async () => {
const normalizedImageResult = await normalizer.normalizeWithConfirmedQuad();
if(normalizedImageResult) {
// Show the normalized image in a Canvas
const cvs = normalizedImageResult.image.toCanvas();
document.querySelector("#normalized-result").appendChild(cvs);
console.log(normalizedImageResult);
}
});
// Start scanning document boundaries.
await normalizer.startScanning(true);
})();
The APIs for this class include
Initialization Control
| Method | Description |
|---|---|
| license | Uses an alphanumeric string to specify the license. |
| createInstance() | Creates a DocumentNormalizer instance. |
| dispose() | Dispose the DocumentNormalizer instance. |
| disposed | Returns whether the instance has been disposed. |
| engineResourcePath | Specifies the path from where the engine and models, etc. can be loaded. |
| loadWasm() | Loads the engine. |
| isWasmLoaded() | Returns whether the engine has been loaded. |
| getVersion() | Returns the version of the library. |
Video Detecting Methods
| Method | Description |
|---|---|
| setImageSource() | Sets an image source for continous scanning. |
| onQuadDetected | This event is triggered when a new quadrilateral is detected. |
| setQuadResultFilter() | Sets a function to filter a detected quadrilateral. |
| confirmQuadForNormalization() | Confirms which quadrilateral will be referred for later normalization. |
| normalizeWithConfirmedQuad() | Normalizes the image whith a selected quadrilateral. |
| startScanning() | Opens the camera and starts continuous scanning of incoming images. |
| pauseScanning() | Pauses continuous scanning but keep the video stream. |
| resumeScanning() | Resumes continuous scanning. |
| stopScanning() | Stops continuous scanning and closes the video stream. |
Detect and Normalize Methods
| Method | Description |
|---|---|
| detectQuad() | Detects quadrilaterals from an image. |
| normalize() | Normalizes the source image based on the settings in options. |
Scan Settings Methods
| Method | Description |
|---|---|
| getScanSettings() | Returns the current ScanSettings. |
| updateScanSettings() | Updates scan settings with the object passed in. |
Runtime Settings Methods
| Method | Description |
|---|---|
| getRuntimeSettings() | Gets runtime settings with a template represented by a JSON object. |
| setRuntimeSettings() | Sets runtime settings with a JSON object. |
| resetRuntimeSettings() | Resets all parameters to default values. |
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