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Refactoring node-flavored frame_grabber

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This commit is contained in:
Christoph Oberhofer
2015-09-13 23:11:48 +02:00
parent abe1458c58
commit ed39bd10ce
1 changed files with 26 additions and 31 deletions
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lib/frame_grabber.js
+26 -31
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@@ -15,17 +15,23 @@ define(["cv_utils"], function(CVUtils) {
_video_size = CVUtils.imageRef(inputStream.getRealWidth(), inputStream.getRealHeight()),
_canvasSize = inputStream.getCanvasSize(),
_size = CVUtils.imageRef(inputStream.getWidth(), inputStream.getHeight()),
topRight = inputStream.getTopRight(),
_topRight = inputStream.getTopRight(),
_data = new Uint8Array(_size.x * _size.y),
_grayData = new Uint8Array(_video_size.x * _video_size.y),
_canvasData = new Uint8Array(_canvasSize.x * _canvasSize.y);
_canvasData = new Uint8Array(_canvasSize.x * _canvasSize.y),
_grayImageArray = Ndarray(_grayData, [_video_size.y, _video_size.x]).transpose(1, 0),
_canvasImageArray = Ndarray(_canvasData, [_canvasSize.y, _canvasSize.x]).transpose(1, 0),
_targetImageArray = _canvasImageArray.hi(_topRight.x + _size.x, _topRight.y + _size.y).lo(_topRight.x, _topRight.y),
_stepSizeX = _video_size.x/_canvasSize.x,
_stepSizeY = _video_size.y/_canvasSize.y;
console.log("FrameGrabber", JSON.stringify({
size: _size,
topRight: topRight,
videoSize: _video_size,
canvasSize: _canvasSize
}));
videoSize: _grayImageArray.shape,
canvasSize: _canvasImageArray.shape,
stepSize: [_stepSizeX, _stepSizeY],
size: _targetImageArray.shape,
topRight: _topRight
}, null, 2));
/**
* Uses the given array as frame-buffer
@@ -46,51 +52,40 @@ define(["cv_utils"], function(CVUtils) {
* The image-data is converted to gray-scale and then half-sampled if configured.
*/
_that.grab = function() {
var doHalfSample = _streamConfig.halfSample,
frame = inputStream.getFrame();
var frame = inputStream.getFrame();
if (frame) {
this.scaleAndCrop(frame, _video_size, _canvasSize, topRight, _size);
this.scaleAndCrop(frame);
return true;
} else {
return false;
}
};
_that.scaleAndCrop = function(frame, frameSize, canvasSize, topRight, targetSize) {
var grayImageArray = Ndarray(_grayData, [frameSize.y, frameSize.x]).transpose(1, 0),
canvasImageArray = Ndarray(_canvasData, [canvasSize.y, canvasSize.x]).transpose(1, 0),
targetImageArray = canvasImageArray.hi(topRight.x + targetSize.x, topRight.y + targetSize.y).lo(topRight.x, topRight.y),
stepSizeX = frameSize.x/canvasSize.x,
stepSizeY = frameSize.y/canvasSize.y,
x,
_that.scaleAndCrop = function(frame) {
var x,
y;
console.log("Input-size: ", grayImageArray.shape);
console.log("Canvas-size: ", canvasImageArray.shape);
console.log("Target-size: ", targetImageArray.shape);
console.log("Step-size: ", [stepSizeX, stepSizeY]);
// 1. compute full-sized gray image
CVUtils.computeGray(frame.data, _grayData);
// 2. interpolate
for (y = 0; y < canvasSize.y; y++) {
for (x = 0; x < canvasSize.x; x++) {
canvasImageArray.set(x, y, (Interp2D(grayImageArray, x*stepSizeX, y*stepSizeY)) | 0);
for (y = 0; y < _canvasSize.y; y++) {
for (x = 0; x < _canvasSize.x; x++) {
_canvasImageArray.set(x, y, (Interp2D(_grayImageArray, x * _stepSizeX, y * _stepSizeY)) | 0);
}
}
// targetImageArray must be equal to targetSize
if (targetImageArray.shape[0] !== targetSize.x ||
targetImageArray.shape[1] !== targetSize.y) {
if (_targetImageArray.shape[0] !== _size.x ||
_targetImageArray.shape[1] !== _size.y) {
throw new Error("Shapes do not match!");
}
// 3. crop
for (y = 0; y < targetSize.y; y++) {
for (x = 0; x < targetSize.x; x++) {
_data[y*targetSize.x + x] = targetImageArray.get(x, y);
for (y = 0; y < _size.y; y++) {
for (x = 0; x < _size.x; x++) {
_data[y * _size.x + x] = _targetImageArray.get(x, y);
}
}
},