Matlab Template Matching Using FFT

Question

I am struggling with template matching in the Fourier domain in Matlab. Here are my images (the artist is RamalamaCreatures on DeviantArt):

My aim is to p

Answer 1

Just ended up implementing the same with python with similar ideas as @rayryeng's using scipy.fftpack.fftn() / ifftn() functions with the following result on the same target and template images:

import numpy as np
import scipy.fftpack as fp
from skimage.io import imread
from skimage.color import rgb2gray, gray2rgb
import matplotlib.pylab as plt
from skimage.draw import rectangle_perimeter

im = 255*rgb2gray(imread('http://i.stack.imgur.com/FXEy7.jpg'))    # target
im_tm = 255*rgb2gray(imread('http://i.stack.imgur.com/6bTzT.jpg')) # template

# FFT 
F = fp.fftn(im)                   
F_tm = fp.fftn(im_tm, shape=im.shape)

# compute the best match location
F_cc = F * np.conj(F_tm)
c = (fp.ifftn(F_cc/np.abs(F_cc))).real
i, j = np.unravel_index(c.argmax(), c.shape)
print(i, j)
# 214 317

# draw rectangle around the best match location
im2 = (gray2rgb(im)).astype(np.uint8)
rr, cc = rectangle_perimeter((i,j), end=(i + im_tm.shape[0], j + im_tm.shape[1]), shape=im.shape)
for x in range(-2,2):
    for y in range(-2,2):
        im2[rr + x, cc + y] = (255,0,0)

# show the output image
plt.figure(figsize=(10,10))
plt.imshow(im2)
plt.axis('off')
plt.show()

Also, the below animation shows the result obtained while locating a bird's template image inside a set of (target) frames extracted from a video with a flock of birds.

One thing to note: the output is very much dependent on the similarity of the size and shape of the object that is to be matched with the template, if it's quite different from that of the template image, the template may not be matched at all.