def augment_hsv(img, hgain=0.5, sgain=0.5, vgain=0.5):
r = np.random.uniform(-1, 1, 3) * [hgain, sgain, vgain] + 1 # random gains
hue, sat, val = cv2.split(cv2.cvtColor(img, cv2.COLOR_BGR2HSV))
dtype = img.dtype # uint8
x = np.arange(0, 256, dtype=np.int16)
lut_hue = ((x * r[0]) % 180).astype(dtype)
lut_sat = np.clip(x * r[1], 0, 255).astype(dtype)
lut_val = np.clip(x * r[2], 0, 255).astype(dtype)
img_hsv = cv2.merge((cv2.LUT(hue, lut_hue), cv2.LUT(sat, lut_sat), cv2.LUT(val, lut_val))).astype(dtype)
cv2.cvtColor(img_hsv, cv2.COLOR_HSV2BGR, dst=img) # no return needed
def adjust_gamma(image, gamma=1.0):
invGamma = 1.0 / gamma
table = np.array([((i / 255.0) ** invGamma) * 255
for i in np.arange(0, 256)]).astype("uint8")
return cv2.LUT(image, table)
def gm(img, gamma=1.0):
table = []
for i in range(256):
table.append(((i / 255)**gamma) * 255)
table = np.array(table).astype('uint8')
img_dark_new = cv2.LUT(img, table)
return img_dark_new
def adjust_gamma(image, gamma=1.0):
# build a lookup table mapping the pixel values [0, 255] to
# their adjusted gamma values
invGamma = 1.0 / gamma
table = np.array([((i / 255.0) ** invGamma) * 255
for i in np.arange(0, 256)]).astype("uint8")
return cv2.LUT(image, table)
def gamma_transform(img, gamma):
gamma_table = [np.power(x / 255.0, gamma) * 255.0 for x in range(256)]
gamma_table = np.round(np.array(gamma_table)).astype(np.uint8)
dst = cv.LUT(img, gamma_table)
# cv.imshow("1",dst)
# cv.waitKey(0)
# cv.destroyAllWindows()
return dst
def correct_brightness(img,
threshold=0.05,
min_white=150,
max_black=50,
_debug=True):
blurred = cv2.medianBlur(img, 3)
lab = cv2.cvtColor(blurred, cv2.COLOR_BGR2LAB)
# adaptive histogram equalization
lab[:, :, 0] = cv2.createCLAHE(clipLimit=0.7,
tileGridSize=(8, 8)).apply(lab[:, :, 0])
# calculate white and black point
hist = calc_hist(lab[:, :, 0])
cutoff = np.max(hist) * threshold
white = np.max(np.arange(256)[hist > cutoff]) + 10
white = max(white, min_white)
black = np.min(np.arange(256)[hist > cutoff]) / 3
black = min(black, max_black)
# adjust lightness
val_black = np.arange(0, 256) - black
val_white = val_black / (white - black) * 255
table = np.clip(val_white, 0, 255).astype(np.uint8)
lab[:, :, 0] = cv2.LUT(lab[:, :, 0], table)
# increase saturation
sat = 127 * 0.15 # percent
val_sat = (np.arange(0, 256) - sat) / (255 - 2 * sat) * 255
table = np.clip(val_sat, 0, 255).astype(np.uint8)
lab[:, :, 1] = cv2.LUT(lab[:, :, 1], table)
lab[:, :, 2] = cv2.LUT(lab[:, :, 2], table)
output = cv2.cvtColor(lab, cv2.COLOR_LAB2BGR)
if _debug:
import matplotlib.pyplot as plt
plt.figure()
plt.plot(hist)
plt.plot(calc_hist(cv2.cvtColor(output, cv2.COLOR_BGR2LAB)[:, :, 0]))
show_images([img, output], show=False)
return output
def c_hsv_np(img_np, h_gain=0.5, s_gain=0.5, v_gain=0.5):
'''
随机色域 is_safe
:param img_np:
:param h_gain:
:param s_gain:
:param v_gain:
:return:
'''
r = np.random.uniform(-1, 1, 3) * [h_gain, s_gain, v_gain] + 1 # 0.5~1.5之间
hue, sat, val = cv2.split(cv2.cvtColor(img_np, cv2.COLOR_BGR2HSV))
dtype = img_np.dtype # uint8
x = np.arange(0, 256, dtype=np.int16)
lut_hue = ((x * r[0]) % 180).astype(dtype)
lut_sat = np.clip(x * r[1], 0, 255).astype(dtype)
lut_val = np.clip(x * r[2], 0, 255).astype(dtype)
img_hsv = cv2.merge((cv2.LUT(hue, lut_hue), cv2.LUT(sat, lut_sat),
cv2.LUT(val, lut_val))).astype(dtype)
cv2.cvtColor(img_hsv, cv2.COLOR_HSV2BGR, dst=img_np) # no return needed
def adjust_gamma(images, gamma=1.0):
assert (len(images.shape) == 4)
assert (images.shape[3] == 1)
invGamma = 1.0 / gamma
table = np.array([((i / 255.0) ** invGamma) * 255
for i in np.arange(0, 256)]).astype("uint8")
new_images = np.empty(images.shape)
for i in range(images.shape[0]):
new_images[i, :, :, 0] = cv2.LUT(np.array(images[i, :, :, 0],
dtype = np.uint8), table)
return new_images
def gamma(img: np.ndarray, gamma_value=1.0):
"""
use a lookup table to calculate new gamma value of pixels
Args:
img: image as numpy array
gamma_value: factor to darken or lighten image
> 1.0 lighten, <1.0 darken, =1.0 no changes
Returns:
image with adjusted gamma values
"""
inverted = 1.0 / gamma_value
table = np.array([((i / 255.0)**inverted) * 255
for i in np.arange(0, 256)]).astype("uint8")
return cv2.LUT(img, table)
def adjust_gamma(self, image, gamma=1.0):
"""
Image gamma correction
Parameters
----------
image: ndim np.array
image to be transformed by gamma correction
gamma: float
Returns
-------
corrected image as np.array
"""
# build a lookup table mapping the pixel values [0, 255] to their adjusted gamma values
invGamma = 1.0 / gamma
table = np.array([((i / 255.0)**invGamma) * 255
for i in np.arange(0, 256)]).astype("uint8")
# apply gamma correction using the lookup table
return cv2.LUT(image, table)
#3. Escreva um algoritmo que leia a imagem abaixo, e então clareie somente as regiões mais escuras dela:
from cv2 import cv2
import numpy as np
img = cv2.imread("img1.jpg")
gamma = 0.6
lookUpTable = np.empty((1,256), np.uint8)
for i in range(256):
lookUpTable[0,i] = np.clip(pow(i / 255.0, gamma) * 255.0, 0, 255)
res = cv2.LUT(img, lookUpTable)
cv2.imshow("img original", img)
cv2.imshow("res", res)
cv2.waitKey(0)
from cv2 import cv2 as cv
import numpy as np
img = cv.imread("Practica/Input/lake.jpg", 1)
#Ecualización Conjunta
gris = cv.cvtColor(img, cv.COLOR_BGR2GRAY) #conversion gris
hist = cv.calcHist(images = [gris],
channels = [0],
mask = None,
histSize = [256],
ranges = [0, 256])
hist *= 255.0/cv.norm(hist, cv.NORM_L1)
# MAT CV_8UC1
lut = np.zeros((1, 256), dtype = "uint8")
acum = 0.0
for i in range (0,256):
lut[0][i] = acum
acum += hist[i]
res = cv.LUT(img,lut)
cv.imshow("Entrada", img)
cv.imshow("Ecualizada", res)
cv.waitKey(0)
def gamma_transform(img, gamma):
gamma_table = [np.power(x / 255.0, gamma) * 255.0 for x in range(size)]
gamma_table = np.round(np.array(gamma_table)).astype(np.uint8)
return cv2.LUT(img, gamma_table)
def gamma(image, gamma=1.0):
invGamma = 1.0 / gamma
table = np.array([((i / 255.0)**invGamma) * 255
for i in np.arange(0, 256)]).astype("uint8")
# apply gamma correction using the lookup table
return cv2.LUT(image, table)
def data_aug(self, data_dict):
### image data augmentation ###
new_img = data_dict['Image']
angle_aug = random.random() * self.max_rot * 2 - self.max_rot
scale_aug = random.random() * (self.max_scale - self.min_scale) + \
self.min_scale
shift_aug_x = random.random() * \
(self.max_shift * self.posmap_size) * 2 \
- (self.max_shift * self.posmap_size)
shift_aug_y = random.random() * \
(self.max_shift * self.posmap_size) * 2 \
- (self.max_shift * self.posmap_size)
tform = tf.SimilarityTransform(scale=scale_aug,
rotation=np.deg2rad(angle_aug),
translation=(shift_aug_x, shift_aug_y))
shift_y, shift_x = np.array(new_img.shape[:2]) / 2.
tf_shift = tf.SimilarityTransform(translation=[-shift_x, -shift_y])
tf_shift_inv = tf.SimilarityTransform(translation=[shift_x, shift_y])
new_img = tf.warp(new_img, (tf_shift + (tform + tf_shift_inv)).inverse)
# fill blank
border_value = np.mean(new_img[ :3, :], axis=(0, 1)) * 0.25 + \
np.mean(new_img[-3:, :], axis=(0, 1)) * 0.25 + \
np.mean(new_img[:, -3:], axis=(0, 1)) * 0.25 + \
np.mean(new_img[:, :3], axis=(0, 1)) * 0.25
mask = np.sum(new_img.reshape(-1, 3), axis=1) == 0
mask = mask[:, np.newaxis]
mask = np.concatenate((mask, mask, mask), axis=1)
border_value = np.repeat(border_value[np.newaxis, :],
mask.shape[0],
axis=0)
border_value *= mask
new_img = (new_img.reshape(-1, 3) + border_value)
new_img = new_img.reshape(self.img_size, self.img_size, 3)
new_img = (new_img * 255.).astype('uint8')
# gamma correlation
gamma = random.random() * (1.8 - 1.0) + 1.0
invGamma = 1.0 / gamma
table = np.array([((i / 255.0)**invGamma) * 255
for i in np.arange(0, 256)]).astype(np.uint8)
new_img = cv2.LUT(new_img, table)
# noise
noise_aug = random.random() * self.max_noise_var
new_img = (skimage.util.random_noise(
new_img, mode="gaussian", var=noise_aug) * 255).astype(np.uint8)
# blur
blur_aug = random.randint(self.min_blur_resize, self.img_size)
new_img = cv2.resize(cv2.resize(new_img, (blur_aug, blur_aug)),
(self.img_size, self.img_size))
# gray
if random.random() < 0.2:
new_img = cv2.cvtColor(new_img, cv2.COLOR_BGR2GRAY)
new_img = np.stack((new_img, ) * 3, axis=-1)
data_dict['Image'] = new_img
# aug posmap
posmap = data_dict['Posmap']
vertices = np.reshape(posmap, [-1, 3]).T
z = vertices[2, :].copy() / tform.params[0, 0]
vertices[2, :] = 1
vertices = np.dot((tf_shift + (tform + tf_shift_inv)).params, vertices)
vertices = np.vstack((vertices[:2, :], z))
posmap = np.reshape(vertices.T,
[self.posmap_size, self.posmap_size, 3])
data_dict['Posmap'] = posmap
return data_dict