fixed rct color transfer function, incorrectly clip colors before

This commit is contained in:
iperov 2021-10-23 09:53:40 +04:00
parent 1aa9463edf
commit 7326771c02
4 changed files with 50 additions and 85 deletions

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@ -1,7 +1,9 @@
import cv2
import numexpr as ne
import numpy as np
from numpy import linalg as npla
import scipy as sp
from numpy import linalg as npla
def color_transfer_sot(src,trg, steps=10, batch_size=5, reg_sigmaXY=16.0, reg_sigmaV=5.0):
"""
@ -133,89 +135,57 @@ def color_transfer_idt(i0, i1, bins=256, n_rot=20):
return np.clip ( d0.T.reshape ( (h,w,c) ).astype(i0.dtype) , 0, 1)
def reinhard_color_transfer(target, source, clip=False, preserve_paper=False, source_mask=None, target_mask=None):
"""
Transfers the color distribution from the source to the target
image using the mean and standard deviations of the L*a*b*
color space.
def reinhard_color_transfer(target : np.ndarray, source : np.ndarray, target_mask : np.ndarray = None, source_mask : np.ndarray = None, mask_cutoff=0.5) -> np.ndarray:
"""
Transfer color using rct method.
This implementation is (loosely) based on to the "Color Transfer
between Images" paper by Reinhard et al., 2001.
target np.ndarray H W 3C (BGR) np.float32
source np.ndarray H W 3C (BGR) np.float32
Parameters:
-------
source: NumPy array
OpenCV image in BGR color space (the source image)
target: NumPy array
OpenCV image in BGR color space (the target image)
clip: Should components of L*a*b* image be scaled by np.clip before
converting back to BGR color space?
If False then components will be min-max scaled appropriately.
Clipping will keep target image brightness truer to the input.
Scaling will adjust image brightness to avoid washed out portions
in the resulting color transfer that can be caused by clipping.
preserve_paper: Should color transfer strictly follow methodology
layed out in original paper? The method does not always produce
aesthetically pleasing results.
If False then L*a*b* components will scaled using the reciprocal of
the scaling factor proposed in the paper. This method seems to produce
more consistently aesthetically pleasing results
target_mask(None) np.ndarray H W 1C np.float32
source_mask(None) np.ndarray H W 1C np.float32
mask_cutoff(0.5) float
Returns:
-------
transfer: NumPy array
OpenCV image (w, h, 3) NumPy array (uint8)
"""
masks are used to limit the space where color statistics will be computed to adjust the target
reference: Color Transfer between Images https://www.cs.tau.ac.il/~turkel/imagepapers/ColorTransfer.pdf
"""
source = cv2.cvtColor(source, cv2.COLOR_BGR2LAB)
target = cv2.cvtColor(target, cv2.COLOR_BGR2LAB)
# convert the images from the RGB to L*ab* color space, being
# sure to utilizing the floating point data type (note: OpenCV
# expects floats to be 32-bit, so use that instead of 64-bit)
source = cv2.cvtColor(source, cv2.COLOR_BGR2LAB).astype(np.float32)
target = cv2.cvtColor(target, cv2.COLOR_BGR2LAB).astype(np.float32)
source_input = source
if source_mask is not None:
source_input = source_input.copy()
source_input[source_mask[...,0] < mask_cutoff] = [0,0,0]
target_input = target
if target_mask is not None:
target_input = target_input.copy()
target_input[target_mask[...,0] < mask_cutoff] = [0,0,0]
# compute color statistics for the source and target images
src_input = source if source_mask is None else source*source_mask
tgt_input = target if target_mask is None else target*target_mask
(lMeanSrc, lStdSrc, aMeanSrc, aStdSrc, bMeanSrc, bStdSrc) = lab_image_stats(src_input)
(lMeanTar, lStdTar, aMeanTar, aStdTar, bMeanTar, bStdTar) = lab_image_stats(tgt_input)
target_l_mean, target_l_std, target_a_mean, target_a_std, target_b_mean, target_b_std, \
= target_input[...,0].mean(), target_input[...,0].std(), target_input[...,1].mean(), target_input[...,1].std(), target_input[...,2].mean(), target_input[...,2].std()
source_l_mean, source_l_std, source_a_mean, source_a_std, source_b_mean, source_b_std, \
= source_input[...,0].mean(), source_input[...,0].std(), source_input[...,1].mean(), source_input[...,1].std(), source_input[...,2].mean(), source_input[...,2].std()
# not as in the paper: scale by the standard deviations using reciprocal of paper proposed factor
target_l = target[...,0]
target_l = ne.evaluate('(target_l - target_l_mean) * source_l_std / target_l_std + source_l_mean')
# subtract the means from the target image
(l, a, b) = cv2.split(target)
l -= lMeanTar
a -= aMeanTar
b -= bMeanTar
target_a = target[...,1]
target_a = ne.evaluate('(target_a - target_a_mean) * source_a_std / target_a_std + source_a_mean')
target_b = target[...,2]
target_b = ne.evaluate('(target_b - target_b_mean) * source_b_std / target_b_std + source_b_mean')
if preserve_paper:
# scale by the standard deviations using paper proposed factor
l = (lStdTar / lStdSrc) * l
a = (aStdTar / aStdSrc) * a
b = (bStdTar / bStdSrc) * b
else:
# scale by the standard deviations using reciprocal of paper proposed factor
l = (lStdSrc / lStdTar) * l
a = (aStdSrc / aStdTar) * a
b = (bStdSrc / bStdTar) * b
np.clip(target_l, 0, 100, out=target_l)
np.clip(target_a, -127, 127, out=target_a)
np.clip(target_b, -127, 127, out=target_b)
# add in the source mean
l += lMeanSrc
a += aMeanSrc
b += bMeanSrc
return cv2.cvtColor(np.stack([target_l,target_a,target_b], -1), cv2.COLOR_LAB2BGR)
# clip/scale the pixel intensities to [0, 255] if they fall
# outside this range
l = _scale_array(l, clip=clip)
a = _scale_array(a, clip=clip)
b = _scale_array(b, clip=clip)
# merge the channels together and convert back to the RGB color
# space, being sure to utilize the 8-bit unsigned integer data
# type
transfer = cv2.merge([l, a, b])
transfer = cv2.cvtColor(transfer.astype(np.uint8), cv2.COLOR_LAB2BGR)
# return the color transferred image
return transfer
def linear_color_transfer(target_img, source_img, mode='pca', eps=1e-5):
'''
@ -353,9 +323,7 @@ def color_transfer(ct_mode, img_src, img_trg):
if ct_mode == 'lct':
out = linear_color_transfer (img_src, img_trg)
elif ct_mode == 'rct':
out = reinhard_color_transfer ( np.clip( img_src*255, 0, 255 ).astype(np.uint8),
np.clip( img_trg*255, 0, 255 ).astype(np.uint8) )
out = np.clip( out.astype(np.float32) / 255.0, 0.0, 1.0)
out = reinhard_color_transfer(img_src, img_trg)
elif ct_mode == 'mkl':
out = color_transfer_mkl (img_src, img_trg)
elif ct_mode == 'idt':
@ -365,4 +333,4 @@ def color_transfer(ct_mode, img_src, img_trg):
out = np.clip( out, 0.0, 1.0)
else:
raise ValueError(f"unknown ct_mode {ct_mode}")
return out
return out

View File

@ -170,10 +170,7 @@ def MergeMaskedFace (predictor_func, predictor_input_shape,
if 'seamless' not in cfg.mode and cfg.color_transfer_mode != 0:
if cfg.color_transfer_mode == 1: #rct
prd_face_bgr = imagelib.reinhard_color_transfer ( np.clip( prd_face_bgr*wrk_face_mask_area_a*255, 0, 255).astype(np.uint8),
np.clip( dst_face_bgr*wrk_face_mask_area_a*255, 0, 255).astype(np.uint8), )
prd_face_bgr = np.clip( prd_face_bgr.astype(np.float32) / 255.0, 0.0, 1.0)
prd_face_bgr = imagelib.reinhard_color_transfer ( prd_face_bgr*wrk_face_mask_area_a, dst_face_bgr*wrk_face_mask_area_a )
elif cfg.color_transfer_mode == 2: #lct
prd_face_bgr = imagelib.linear_color_transfer (prd_face_bgr, dst_face_bgr)
elif cfg.color_transfer_mode == 3: #mkl
@ -252,9 +249,7 @@ def MergeMaskedFace (predictor_func, predictor_input_shape,
if 'seamless' in cfg.mode and cfg.color_transfer_mode != 0:
if cfg.color_transfer_mode == 1:
out_face_bgr = imagelib.reinhard_color_transfer ( np.clip(out_face_bgr*wrk_face_mask_area_a*255, 0, 255).astype(np.uint8),
np.clip(dst_face_bgr*wrk_face_mask_area_a*255, 0, 255).astype(np.uint8) )
out_face_bgr = np.clip( out_face_bgr.astype(np.float32) / 255.0, 0.0, 1.0)
out_face_bgr = imagelib.reinhard_color_transfer (out_face_bgr*wrk_face_mask_area_a, dst_face_bgr*wrk_face_mask_area_a)
elif cfg.color_transfer_mode == 2: #lct
out_face_bgr = imagelib.linear_color_transfer (out_face_bgr, dst_face_bgr)
elif cfg.color_transfer_mode == 3: #mkl

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@ -1,5 +1,6 @@
tqdm
numpy==1.19.3
numexpr
h5py==2.10.0
opencv-python==4.1.0.25
ffmpeg-python==0.1.17

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@ -1,5 +1,6 @@
tqdm
numpy==1.19.3
numexpr
h5py==2.10.0
opencv-python==4.1.0.25
ffmpeg-python==0.1.17