Write a function that saves the image as a specified file. $(15\backslash \%)$

$-$ In the parameter list, it supplies two image filenames, k$,$ ratio and output filename

$-$ Suppose the first image is the query, the second image is the scene

$-$ Load the images and convert them to grayscale

$-$ Run SIFT detectors on both grayscale images

$-$ Use knnMatch with the value of $\backslash ($ k $\backslash )$ to compare the SIFT descriptors

$-$ Use a ratio test with the value of ratio to identify the common descriptors

$-$ Use drawMatchesKnn to draw the list of matches onto the images

$-$ Stack the two images horizontally

$-$ Save the plots as the specified output filename. Do not show the plots.

This problem is about image processing and data visualization.

Note: You may refer to cv$2.$BFMatcher$()$:

Code:

$```$

# Problem $3$

def problem$\_3($imageA$,$ imageB, output$="$q$3.$jpg$")$:

# write your logic here

plt$.$savefig$($output$)$ # do not show the plt

$```$

Execution:

$```$

$>$ imageA $=$ "image$3$a$.$jpg$"$

$>$ imageB $=$ "image$3$b$.$jpg$"$

$>$ problem$\_3($imageA$,$ imageB, $"$q$3.$png$")$

$```$