Algorithm 1. Left-flipping algorithm.

Data: $img=inputImage$

Result: leftImg

$vertSum\leftarrow []$;

$i\leftarrow 0$;

$isLeftSide\leftarrow False$;

for $col\in img$ do

$vertSum[i]=\sum (col)$;

$i=i+1$

end

if ${\sum }_{i=0}^{len(vertSum/2)}(vertSum[i])\ge {\sum }_{i=len(vertSum/2)}^{len(vertSum)}(vertSum[i])$ then

$isLeftSide=True$

end

if not isLeftSide then

$img=verticalFlip(img)$

end

$leftImg\leftarrow img$