LoCoBoard: Low-Cost Interactive Whiteboard Using Computer Vision Algorithms

Algorithm 2

Pseudo code Algorithm A2.

function ALGORITHM (image_height, image_width, image, threshold, step)𝐫𝐞𝐭𝐮𝐫𝐧 coordinates of the  PL centroid

inputs:       image_height, height of the image

     image_width, width of the image

     image, captured grayscale image

     threshold, lower limit of brightness to identify pixels belonging to PL blob

     step, interval between consecutive processed pixels per row during search

size ← 0

colValue ← 0

rowValue ← 0

index ← 0

 while index < image_height ⋆ image_width do

  row ← index/image_width

  column ← index % image_width

  𝐢𝐟image[row][column] ≥threshold then

   colValue ← colValue +column

   rowValue ← rowValue +row

   size ← size +1

  index ← index + step

colValue ← colValue/size

rowValue ← rowValue/size

return (rowValue, colValue)