Pyramid Functions

This palette contains pyramid functions.

Note: An vi icon with yellow background means they work on color images. With gray background means they only work on single channel image. With half yellow and half gray background means they work on both color and single channel image. Others vi icon background are for either examples or high level vis. For controls descriptions, you need to go to the vi in LabVIEW, use help (ctrl+H) and move mouse over the controls to see them.

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IVision_PyrDown.vi

The function performs downsampling step of Gaussian pyramid

decomposition. First it convolves source image with the Gaussian_5x5 filter and then

downsamples the image by rejecting even rows and columns. So the destination image

is four times smaller than the source image. So be sure to set the size of the destination image to be 1/4 of the source image.

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IVision_PyrUp.vi

The function performs up-sampling step of Gaussian pyramid decomposition.

First it upsamples the source image by injecting even zero rows and columns and then

convolves result with Gaussian_5x5 filter multiplied by 4 for interpolation. So the

destination image is four times larger than the source image.

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IVision_PyrSegmentation.vi

The function implements image segmentation by pyramids. The pyramid builds up to the level level. The links between any pixel a on level i and its candidate father pixel b on the adjacent level are established if

p(c(a),c(b))<threshold1. After the connected components are defined, they are joined into several clusters. Any two segments A and B belong to the same cluster, if

p(c(A),c(B))<threshold2. The input image has only one channel, then

p(c¹,c²)=|c¹-c²|. If the input image has three channels (red, green and blue), then

p(c¹,c²)=0,3·(c¹r-c²r)+0,59·(c¹g-c²g)+0,11·(c¹b-c²b) . There may be more than one connected component per a cluster.

The images src and dst should be 8-bit single-channel or 3-channel images or equal size

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