Function:OpticalFlowPyrLK - Revision history

Ghazanfar: Created page with "NOTOC Computes Dense Optical Flow between each pixel of two images using pyramidal Lucas-Kanade method. ===Function=== {| |style="font-size:150%;"|
2012-05-14T07:12:26Z

Created page with "NOTOC Computes Dense Optical Flow between each pixel of two images using pyramidal Lucas-Kanade method. ===Function=== {| |style="font-size:150%;"| <syntaxhighlight lang="..."

New page
NOTOC
Computes Dense Optical Flow between each pixel of two images using pyramidal Lucas-Kanade method.
===Function===
{|
|style="font-size:150%;"|
<syntaxhighlight lang="cpp">
CuviStatus opticalFlowPyrLKDense(CuviImage* previousImage,
CuviImage* nextImage,
Cuvi32f* flowX
Cuvi32f* flowY,
CuviTrackingCriteria criteria,
CuviStream* stream = NULL);
</syntaxhighlight>
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===Parameters===
{|class="wikitable"
|-
! Name
! Type
! Description
|-
| previousImage
| CuviImage*
| The first image whose features are to be tracked
|-
| nextImage
| CuviImage*
| Second image, in which to look for features of first image
|-
| flowX
| Cuvi32f*
| Horizontal optical flow
|-
| flowY
| Cuvi32f*
| Vertical optical flow
|-
| criteria
| CuviFeaturesCriteria
| A structure containing various parameters that affect optical flow calculation
|-
| stream
| CuviStream*
| GPU stream ID for execution

|}

===Image Type Support===

{| class="wikitable"
|-
! Input
! Output
|-
| 2x 8uC1
| 2x Cuvi32f*
|}

===Samples===
{|
|-
|[[File:OF_frame1.png|frame|First Input Image (8-bit)]]
|[[File:OF_frame2.png|frame|Second Input Image (8-bit)]]
|-
|[[File:OF_flowMag.png|frame| Optical Flow Magnitude]]
|[[File:OF_sparseFlow.png|frame| Flow of selected points]]
|}

===Example===
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|style="font-size:150%;"|
<syntaxhighlight lang="cpp">

//Image size
CuviSize size = cuviSize(width,height);

//Create two 8-bit Grays-scale CuviImage objects
CuviImage* gimg1 = new CuviImage(size,8,1);
CuviImage* gimg2 = new CuviImage(size,8,1);

//Populate the GPU Images
gimg1->upload(img1->imageData,img1->widthStep);
gimg2->upload(img2->imageData,img2->widthStep);

Cuvi32f* flowX = new float[width * height];
Cuvi32f* flowY = new float[width * height];

//tracking criteria
CuviTrackingCriteria tc = cuviTrackingCriteria(2,cuviSize(12,12));

//Compute optical flow between first frame and second frame
cuvi::computerVision::opticalFlowPyrLKDense(gimg1,gimg2,flowX,flowY,tc);

</syntaxhighlight>
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