Frame Acquisition
| Name | Description |
|---|---|
| setScanRegion() | Specifies which part of the original video is considered when processing frames. |
| getScanRegion() | Returns the scan region. |
| getFrame() | Returns a DCEFrame object which contains the image data of the latest frame from the video input. |
| getFrameFromBuffer() | Returns a DCEFrame object which contains the image data of the specified buffered frame. |
| startFetchingLoop() | Starts a fetching loop that continuously put frames in a buffer. |
| stopFetchingLoop() | Stops the fetching loop. |
| isFetchingLoopStarted() | Returns the state of the fetching loop. |
| maxNumberOfFramesInBuffer | Sets or returns how many frames can be buffered. |
| numberOfFramesInBuffer | Returns how many frames there are in the buffer. |
| loopInterval | Returns or sets the start time of the next fetch operation. |
| singleFrameMode | Returns or sets whether to enable the singe-frame mode. |
setScanRegion
Specifies which part of the original video is considered when processing frames.
setScanRegion(region: Region): void;
Parameters
region: a Region object that specifies a part of the video.
Return value
None.
Code Snippet
let region = {
regionLeft: 25,
regionTop: 25,
regionRight: 75,
regionBottom: 75,
regionMeasuredByPercentage: true
};
enhancer.setScanRegion(region);
See also
getScanRegion
Returns the scan region.
getScanRegion(): Region;
Parameters
None.
Return value
A Region object which specifies the scan region.
Code Snippet
let region = enhancer.getScanRegion();
See also
getFrame
Returns a DCEFrame object which contains the image data of the latest frame from the video input.
getFrame(): DCEFrame;
Parameters
None.
Return value
A DCEFrame object which contains the image data of the frame and related information.
Code Snippet
let frameData = enhancer.getFrame();
document.body.appendChild(frameData.canvas);
See also
getFrameFromBuffer
Returns a DCEFrame object which contains the image data of the specified buffered frame.
getFrameFromBuffer(index?: number): DCEFrame;
Parameters
index: specifies which buffered frame to return when maxNumberOfFramesInBuffer is bigger than 1. If not specified, the first buffered frame is returned.
Return value
A DCEFrame object which contains the image data of the frame and related information.
Code Snippet
let frameData = enhancer.getFrameFromBuffer();
document.body.appendChild(frameData.canvas);
See also
startFetchingLoop
Starts a fetching loop that continuously put frames in a buffer.
When the API is called, the SDK immediately fetches a frame and puts it into the buffer, then waits for the time set by “loopInterval” before fetching the next frame, and so on.
startFetchingLoop(): void;
Parameters
None.
Return value
None.
See also
stopFetchingLoop
Stops the fetching loop and clears the frames buffer.
stopFetchingLoop(): void;
Parameters
None.
Return value
None.
isFetchingLoopStarted
Returns the state of the fetching loop.
isFetchingLoopStarted(): Boolean;
Parameters
None.
Return value
None.
maxNumberOfFramesInBuffer
Sets or returns how many frames can be buffered.
maxNumberOfFramesInBuffer: number;
numberOfFramesInBuffer
Returns how many frames there are in the buffer.
readonly numberOfFramesInBuffer: number;
loopInterval
Returns or sets the start time of the next fetch operation.
loopInterval: number;
See also
singleFrameMode
Returns or sets whether to enable the singe-frame mode. When the single-frame mode is enabled, the video will not stream in the built-in UI of the library. Instead, the user can click the UI to invoke the system camera interface to catch a frame or select an existing image from the device storage.
To get the actual data, add a event handler to the event ‘singleFrameAcquired’.
singleFrameMode: boolean;
Code Snippet
let pEnhancer = null;
(async () => {
let enhancer = await (pEnhancer = pEnhancer || Dynamsoft.DCE.CameraEnhancer.createInstance());
enhancer.on('singleFrameAcquired', frame => {
document.body.appendChild(frameData.canvas);
});
enhancer.singleFrameMode = true;
await enhancer.open();
})();
Yes
No