i am biggner in image processing and in gabor filter and i want to use this filter to enhance fingerprint image
i read many articles about fingerprint image enhancement and i know that the steps for that is
read image -> noramalize -> get orientation map -> gabor filter -> binarize -> skeleton
now i am in step 4 , my question is how to get the right values for ( lambds and gamma ) for gabor
filter
my image :
my code :
1- read image and get the orientation map using HOG features
imgc = imread(r'C:\Users\iP\Desktop\printe.jpg',as_gray=True)
imgc = resize(imgc, (64*3,128*3))
rows,cols=imgc.shape
offset=24
ori=9 # to get angels (0,45,90,135) only
fd, hog_image = hog(imgc, orientations=ori, pixels_per_cell=(offset, offset),
cells_per_block=(1, 1), visualize=True, multichannel=None,feature_vector=False
)
orientation map :
2- reshape the orientation map from (8, 16, 1, 1, 9) to (8, 16, 9),,, 8 ->rows , 16 -> cols , 9 orientation
fd=np.array(fd)
fd=np.reshape(fd,(fd.shape[0],fd.shape[1],ori))
# from (8, 16, 9) to (8, 16, 1)
# Choose the angle that has the most potential ( biggest magntude )
angels=np.zeros((fd.shape[0],fd.shape[1],1))
for r in range(fd.shape[0]):
for c in range(fd.shape[1]):
bloc_prop = fd[r,c]
angelss=bloc_prop.reshape((1,ori))
angel=np.argmax(angelss)
angels[r,c]=angel
angels=angels.astype(np.int32)
3- the convolve function
def conv_gabor(img,orient_map,gabor_kernel_shape):
#
# loop on all pixels in the image and convolve it with it's angel in the orientation map
#
roo,coo=img.shape
#to get the padding value for immage before convolving it with kernels
pad=(gabor_kernel_shape-1)
padded=np.zeros((img.shape[0]+pad,img.shape[1]+pad)) # adding the cols and rows
padded[int(pad/2):-int(pad/2),int(pad/2):-int(pad/2)]=img # copy image to inside the padded
image
#result image
dst=padded.copy()
# start from the image that inside the padded
for r in range(int(pad/2),int(pad/2)+roo):
for c in range(int(pad/2),int(pad/2)+coo):
# get the angel from the orientation map
ro=(r-int(pad/2))//offset
co=(c-int(pad/2))//offset
ang=angels[ro,co]
real_angel=(((180/ori)*ang))
# bloack around the pixe to convolve it
block=padded[r-int(pad/2):r+int(pad/2)+1,c-int(pad/2):c+int(pad/2)+1]
# get Gabor kernel
# here is my question ->> what to get the parametres values for ( lambda and gamma
and phi)
ker= cv2.getGaborKernel( (gabor_kernel_shape,gabor_kernel_shape), 3,
np.deg2rad(real_angel),np.pi/4,0.001,0 )
dst[r,c]=np.sum((ker*block))
return dst
dst=conv_gabor(imgc,angels,11)
dst :
you see the image is too bad i dont know why this , i think because the lambda and gamma or what ?
but when i filter with one angel only 45 :
ker= cv2.getGaborKernel( (11,11), 2, np.deg2rad(45),np.pi/4,0.5,0 )
filt = cv2.filter2D(imgc,cv2.CV_64F,ker)
plt.imshow(filt,'gray')
reslut :
you see the edges that has 45 on the left is good quality
can anyone help me please , and tell me what should i do in this probelm ?
thanks all :)
EDIT:
i searched for another way and i found that i can use gabor fiter bank with many orientation and get best score in filtred images , so how can i find best score for pixels from filtred images
this is the output when i use gabor fiter bank with 45,60,65,90,135 angels and divide the filtered images to 16*16 and find the highest standard deviation (best score -> i use standard deviation as the score) for each block and get the best filtred image
so as you can see there are good and bad parts in the image ,i think using standard deviation alone is ineffective in some parts of the image , so my new question is what is best score function that gives me good output parts in the image






