Class CameraEnhancer

Frame Acquisition

setScanRegion

Specifies which part of the original video is considered when processing frames.

setScanRegion(region: Rect | DSRect): void;

Parameters

region: a Rect or DSRect object that specifies a part of the video.

Return value

None.

Code Snippet

let scanRegion = {
    x: 25,
    y: 75,
    width: 25,
    height: 75,
    isMeasuredInPercentage: true
};
cameraEnhancer.setScanRegion(scanRegion); 
//...
cameraEnhancer.setScanRegion(null); //Cancel the scan region.

See also

Rect

DSRect

getScanRegion

Returns the scan region.

getScanRegion(): Rect | DSRect;

Parameters

None.

Return value

A Rect or DSRect object which specifies the scan region.

Code Snippet

let region = cameraEnhancer.getScanRegion();

See also

DSRect

fetchImage

Returns a DCEFrame object which contains the image data of the latest frame from the video input.

fetchImage(): DCEFrame;

Parameters

None.

Return value

A DCEFrame object which contains the image data of the frame and related information.

Code Snippet

let image = cameraEnhancer.fetchImage();
document.body.appendChild(image.toCanvas());

See also

DCEFrame

addImageToBuffer

Adds an DSImageData object to the buffer.

addImageToBuffer(image: DSImageData): void;

Parameters

image: the image to be added to buffer.

Return value

None.

Code Snippet

let image = cameraEnhancer.fetchImage();
cameraEnhancer.addImageToBuffer(image);

setImageFetchInterval

Sets the interval at which startFetching() is called when continued fetching has started.

setImageFetchInterval(interval: number): void;

Parameters

interval: specifies the interval in milliseconds.

Return value

None.

Code Snippet

cameraEnhancer.setImageFetchInterval(200);

getImageFetchInterval

Returns the fetch interval.

getImageFetchInterval(): number;

Parameters

None.

Return value

The fetch interval.

Code Snippet

let fetchInterval = cameraEnhancer.getImageFetchInterval();

startFetching

Starts to continuously fetch images and put them into the buffer.

startFetching(): void;

Parameters

None.

Return value

None.

Code Snippet

cameraEnhancer.startFetching();

stopFetching

Stops fetching any more images.

stopFetching(): void;

Parameters

None.

Return value

None.

Code Snippet

cameraEnhancer.stopFetching();

setMaxImageCount

Sets the size of the buffer as in how many images can be buffered.

setMaxImageCount: (count: number) void;

Parameters

count: specifies how many images can be held in buffer.

Return value

None.

Code Snippet

cameraEnhancer.setMaxImageCount(10);

getMaxImageCount

Returns the size of the buffer.

getMaxImageCount(): number;

Parameters

None.

Return value

A number indicating how many images can be held in buffer.

Code Snippet

let bufferSize = cameraEnhancer.getMaxImageCount();

getImageCount

Returns how many images are in buffer.

getImageCount(): number;

Parameters

None.

Return value

A number indicating how many images are held in buffer.

Code Snippet

let imageCount = cameraEnhancer.getImageCount();

hasImage

Checks whether an image exists. The image is specified by its id.

hasImage(imageId: number): boolean;

Parameters

imageId: specifies an image by its id.

Return value

True means the image exists in the buffer, false the opposite.

Code Snippet

let imageCount = cameraEnhancer.hasImage(10);

getImage

Returns a DCEFrame object from the buffer.

This function retrieves the latest image added to the buffer, and removing it from the buffer in the process.

getImage(): DCEFrame;

Parameters

None.

Return value

A DCEFrame object which contains the image data of the frame and related information.

Code Snippet

let image = cameraEnhancer.getImage();
document.body.appendChild(image.toCanvas());

See also

DCEFrame

setNextImageToReturn

Specifies an image by its id to be returned when getImage() is called the next time.

setNextImageToReturn(imageId: number, keepInBuffer?: boolean): void;

Parameters

imageId: specifies the image by its id.

• keepInBuffer(optional): specifies whether to keep the image in buffer after it is returned.

Return value

None.

Code Snippet

cameraEnhancer.setNextImageToReturn(10);
let image = cameraEnhancer.getImage();
document.body.appendChild(image.toCanvas());

setBufferOverflowProtectionMode

Sets a protection mode that determines what happens when the buffer overflows.

setBufferOverflowProtectionMode(mode:EnumBufferOverflowProtectionMode): void;

Parameters

mode: specifies the protection mode.

Return value

None.

Code Snippet

cameraEnhancer.setBufferOverflowProtectionMode(EnumBufferOverflowProtectionMode.BOPM_Append);

See also

EnumBufferOverflowProtectionMode

getBufferOverflowProtectionMode

Returns the buffer protection mode.

getBufferOverflowProtectionMode(): EnumBufferOverflowProtectionMode;

Parameters

mode: specifies the protection mode.

Return value

None.

Code Snippet

cameraEnhancer.getBufferOverflowProtectionMode(EnumBufferOverflowProtectionMode.BOPM_Append);

See also

EnumBufferOverflowProtectionMode

isBufferEmpty

Returns whether the buffer is empty.

isBufferEmpty(): boolean;

Parameters

None.

Return value

True means the buffer is empty, false the opposite.

Code Snippet

if(cameraEnhancer.isBufferEmpty()) {
    console.log("There is no image in buffer!");
}

hasNextImageToFetch

Checks whether another image can be fetched.

hasNextImageToFetch(): boolean;

Parameters

None.

Return value

True means the input image source can supply more images, false means the input image source is closed or exhausted.

Code Snippet

if(!cameraEnhancer.hasNextImageToFetch()) {
    console.log("The image source is exhausted!");
}

setPixelFormat

Determines the format of the images added to the buffer when the fetchImage() or startFetching() method is called.

setPixelFormat(pixelFormat: EnumImagePixelFormat.IPF_GRAYSCALED
                | EnumImagePixelFormat.IPF_ABGR_8888
                | EnumImagePixelFormat.IPF_ARGB_8888): void;

Parameters

pixelFormat: specifies the format of the image to return.

Return value

None.

Code Snippet

cameraEnhancer.setPixelFormat(EnumImagePixelFormat.IPF_ARGB_8888);
let image = cameraEnhancer.getImage();
document.body.appendChild(image.toCanvas());

See also

EnumImagePixelFormat

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

(async () => {
    let cameraEnhancer = await Dynamsoft.DCE.CameraEnhancer.createInstance();
    cameraEnhancer.on('singleFrameAcquired', frameData => {
        document.body.appendChild(frameData.toCanvas());
    });
    cameraEnhancer.singleFrameMode = true;
    await cameraEnhancer.open(true);
})();

As shown in the code snippet above, singleFrameMode should be set before calling open().

takePhoto

Invokes the system camera to take a frame with better image quality or select an existing image from the device storage.

takePhoto(listener: (dceFrame: DCEFrame) => void): void;

Parameter

listener: The listener callback function expects a single argument of type DCEFrame, representing the data related to the captured photo.

Return Value

None.

Code Snippet

function handleCapturedPhoto(dceFrame) {
  console.log('Captured Photo Data:', dceFrame);
  // Process the captured photo data as needed.
}

// Capture a photo and invoke the listener with the captured data.
cameraEnhancer.takePhoto(handleCapturedPhoto);