def formulas_idwt(img, level=1):
height, width = img.shape
for lev in range(level, 0, -1):
resize = 2**(lev - 1)
fheight, fwidth = height // resize, width // resize
fetch_img = img[:fheight, :fwidth]
show_and_write(fetch_img, "fetch_img")
row_even = fetch_img[:fheight // 2, ::] + fetch_img[fheight //
2:None, ::]
row_odd = fetch_img[:fheight // 2, ::] - fetch_img[fheight //
2:None, ::]
fetch_img[::2, ::] = row_even
fetch_img[1::2, ::] = row_odd
col_even = fetch_img[::, :fwidth // 2] + fetch_img[::,
fwidth // 2:None]
col_odd = fetch_img[::, :fwidth // 2] - fetch_img[::, fwidth // 2:None]
fetch_img[::, ::2] = col_even
fetch_img[::, 1::2] = col_odd
img[:fheight, :fwidth] = fetch_img * coef
return img
def formulas_idwt(img, level=1):
height, width = img.shape
for lev in range(level, 0, -1):
resize = 2 ** (lev - 1)
fheight, fwidth = height // resize, width // resize
fetch_img = img[:fheight, :fwidth]
show_and_write(fetch_img, "fetch_img")
row_even = fetch_img[: fheight // 2, ::] + fetch_img[fheight // 2 : None, ::]
row_odd = fetch_img[: fheight // 2, ::] - fetch_img[fheight // 2 : None, ::]
fetch_img[::2, ::] = row_even
fetch_img[1::2, ::] = row_odd
col_even = fetch_img[::, : fwidth // 2] + fetch_img[::, fwidth // 2 : None]
col_odd = fetch_img[::, : fwidth // 2] - fetch_img[::, fwidth // 2 : None]
fetch_img[::, ::2] = col_even
fetch_img[::, 1::2] = col_odd
img[:fheight, :fwidth] = fetch_img * coef
return img
for lev in range(0, level):
resize = 2**lev
fheight, fwidth = height // resize, width // resize
fetch_img = img[:fheight, :fwidth]
odd_col = fetch_img[::, 1::2]
even_col = fetch_img[::, ::2]
Lc = (even_col + odd_col)
Hc = (even_col - odd_col)
fetch_img = np.append(Lc, Hc, axis=1)
odd_row = fetch_img[1::2, ::]
even_row = fetch_img[::2, ::]
Lr = (even_row + odd_row)
Hr = (even_row - odd_row)
fetch_img = np.append(Lr, Hr, axis=0)
img[:fheight, :fwidth] = fetch_img * coef
return img
if __name__ == '__main__':
img = cv.imread("images/Fig0809(a).tif", 0)
img = img.astype(float)
img = formulas_dwt(img, 7)
show_and_write(img, "trans")
img = formulas_idwt(img, 7)
show_and_write(img, "inv")
for lev in range(0, level):
resize = 2 ** lev
fheight, fwidth = height // resize, width // resize
fetch_img = img[:fheight, :fwidth]
odd_col = fetch_img[::, 1::2]
even_col = fetch_img[::, ::2]
Lc = even_col + odd_col
Hc = even_col - odd_col
fetch_img = np.append(Lc, Hc, axis=1)
odd_row = fetch_img[1::2, ::]
even_row = fetch_img[::2, ::]
Lr = even_row + odd_row
Hr = even_row - odd_row
fetch_img = np.append(Lr, Hr, axis=0)
img[:fheight, :fwidth] = fetch_img * coef
return img
if __name__ == "__main__":
img = cv.imread("images/Fig0809(a).tif", 0)
img = img.astype(float)
img = formulas_dwt(img, 7)
show_and_write(img, "trans")
img = formulas_idwt(img, 7)
show_and_write(img, "inv")
