Arithmetic operation and logic operation of Video

Arithmetic operation and logic operation of Video

1. Addition operation

dst(x,y) = saturate(src1(x,y)+src2(x,y))

• It Add the pixel value that exists on same position between two videos and Set the pixel value of video.
• If the value is more than 255, set the pixel value to 255.

cv2.add(src1, src2, dst=None, mask=None, dtype=None) -> dst

• src1 : (input) first video or schalar
• src2 : (input) second video or schalar
• dst : (output) result video of addition operation
• mask : mask video
• dtype : type of output video

2. Weighted sum

dst(x,y) = saturate(a * src1(x,y) + b * src2(x,y))

• Calculating weighted sum about pixel value which exist same position of two video and Setting the pixel value of result video.

• Genarlly, spacifiy a + b = 1 (Maintaing normal birghtness of two input video)

3. Average operation

dst(x,y) = 1/2(src1(x,y) + src2(x,y))

• Setting the weight with a = b = 0.5

Code of weighted sum

cv2.addWeighted(src1,alpha,src2,beta,gamma,dst=None,dtype=None) -> dst

• src1 : Frist video
• alpha : Weight of first video
• src2 : Second video ( same type & same size with src1)
• beta : Weight of second video
• gamma : Additional added value to result value
• dst : result vieo of weighted sum
• dtype : type of output video(dst)

4. Subtraction operation

dst(x,y) = |src1(x,y) - src2(x,y)

• It doesn’t be effected from order of input video

Code of subtracion operation

cv2.subtract(src1, src2, dst = None, mask = None, dtype = None ) -> dst

• src1 : first video
• src2 : second video
• dst : result video of subtraction operation
• mask : mask video
• dtype : type of output video

5. Bit unit operation ( AND, OR. XOR, NOT)

cv2.bitwise_and(src1, src2, dst = None, mask = None) -> dst
cv2.bitwise_or(src1, src2, dst = None, mask = None) -> dst
cv2.bitwise_xor(src1, src2, dst = None, mask = None) -> dst
cv2.bitwise_not(src1, dst = None, mask = None) -> dst

• src1 : first video
• src2 : second video
• dst : result video
• mask : mask video