ImageBuffer
Image buffer
Helper class grabbing images into internal storage. Used by VideoSource to grab video streams and Engine to resize images for faster processing. Image can be accessed by canvas or read as pixels.
Constructors
Section titled “Constructors”Constructor
Section titled “Constructor”new ImageBuffer(
name):ImageBuffer
Constructor
Parameters
Section titled “Parameters”string = "canvas"
Optional name of canvas
Returns
Section titled “Returns”ImageBuffer
Properties
Section titled “Properties”canvas
Section titled “canvas”canvas:
HTMLCanvasElement
Canvas to capture frames
context
Section titled “context”
protectedcontext:null|CanvasRenderingContext2D=null
Context to capture frames
inputSize
Section titled “inputSize”
protectedinputSize:Size
Size of the input
size:
Size
Size of the frames
transform?
Section titled “transform?”
protectedoptionaltransform: [[number,number,number], [number,number,number]]
Image transformation matrix
Methods
Section titled “Methods”capture()
Section titled “capture()”capture(
video):boolean
Grab frame
Grabs frame from video element or canvas into internal canvas. Automatically rescales an image if resolutions are different.
Parameters
Section titled “Parameters”Element to grab image from
ImageBitmap | HTMLCanvasElement | HTMLVideoElement
Returns
Section titled “Returns”boolean
True if image is grabbed, False otherwise
data()
Section titled “data()”data():
undefined|ImageData
Get image buffer
Returns data buffer of image currently grabbed into canvas.
Returns
Section titled “Returns”undefined | ImageData
Image data buffer on success, undefined otherwise
dispose()
Section titled “dispose()”dispose():
void
Dispose video context object
Returns
Section titled “Returns”void
fill()
Section titled “fill()”fill():
void
Fill canvas with color
Returns
Section titled “Returns”void
setup()
Section titled “setup()”setup(
size,transpose,flip,clip?):void
Set input video size and optional transformations
Transformations are applied in order traspose->flip->clip, mening that if for example transpose and flip.x are set than already transposed image will be flipped horizontally. If transpose is true, ImageBuffer width and height reflect this - they will be swapped against input (original) size.
Parameters
Section titled “Parameters”Video size
transpose
Section titled “transpose”boolean = false
Image transposition
FlipFlags = ...
Image flipping flags
Clipping rectangle in [0..1] space
Returns
Section titled “Returns”void