DeepFaceLab/imagelib/color_transfer.py

396 lines
14 KiB
Python

import cv2
import numpy as np
from numpy import linalg as npla
import scipy as sp
import scipy.sparse
from scipy.sparse.linalg import spsolve
def color_transfer_sot(src,trg, steps=10, batch_size=5, reg_sigmaXY=16.0, reg_sigmaV=5.0):
"""
Color Transform via Sliced Optimal Transfer
ported by @iperov from https://github.com/dcoeurjo/OTColorTransfer
src - any float range any channel image
dst - any float range any channel image, same shape as src
steps - number of solver steps
batch_size - solver batch size
reg_sigmaXY - apply regularization and sigmaXY of filter, otherwise set to 0.0
reg_sigmaV - sigmaV of filter
return value - clip it manually
"""
if not np.issubdtype(src.dtype, np.floating):
raise ValueError("src value must be float")
if not np.issubdtype(trg.dtype, np.floating):
raise ValueError("trg value must be float")
if len(src.shape) != 3:
raise ValueError("src shape must have rank 3 (h,w,c)")
if src.shape != trg.shape:
raise ValueError("src and trg shapes must be equal")
src_dtype = src.dtype
h,w,c = src.shape
new_src = src.copy()
for step in range (steps):
advect = np.zeros ( (h*w,c), dtype=src_dtype )
for batch in range (batch_size):
dir = np.random.normal(size=c).astype(src_dtype)
dir /= npla.norm(dir)
projsource = np.sum( new_src*dir, axis=-1).reshape ((h*w))
projtarget = np.sum( trg*dir, axis=-1).reshape ((h*w))
idSource = np.argsort (projsource)
idTarget = np.argsort (projtarget)
a = projtarget[idTarget]-projsource[idSource]
for i_c in range(c):
advect[idSource,i_c] += a * dir[i_c]
new_src += advect.reshape( (h,w,c) ) / batch_size
if reg_sigmaXY != 0.0:
src_diff = new_src-src
src_diff_filt = cv2.bilateralFilter (src_diff, 0, reg_sigmaV, reg_sigmaXY )
if len(src_diff_filt.shape) == 2:
src_diff_filt = src_diff_filt[...,None]
new_src = src + src_diff_filt
return new_src
def color_transfer_mkl(x0, x1):
eps = np.finfo(float).eps
h,w,c = x0.shape
h1,w1,c1 = x1.shape
x0 = x0.reshape ( (h*w,c) )
x1 = x1.reshape ( (h1*w1,c1) )
a = np.cov(x0.T)
b = np.cov(x1.T)
Da2, Ua = np.linalg.eig(a)
Da = np.diag(np.sqrt(Da2.clip(eps, None)))
C = np.dot(np.dot(np.dot(np.dot(Da, Ua.T), b), Ua), Da)
Dc2, Uc = np.linalg.eig(C)
Dc = np.diag(np.sqrt(Dc2.clip(eps, None)))
Da_inv = np.diag(1./(np.diag(Da)))
t = np.dot(np.dot(np.dot(np.dot(np.dot(np.dot(Ua, Da_inv), Uc), Dc), Uc.T), Da_inv), Ua.T)
mx0 = np.mean(x0, axis=0)
mx1 = np.mean(x1, axis=0)
result = np.dot(x0-mx0, t) + mx1
return np.clip ( result.reshape ( (h,w,c) ).astype(x0.dtype), 0, 1)
def color_transfer_idt(i0, i1, bins=256, n_rot=20):
relaxation = 1 / n_rot
h,w,c = i0.shape
h1,w1,c1 = i1.shape
i0 = i0.reshape ( (h*w,c) )
i1 = i1.reshape ( (h1*w1,c1) )
n_dims = c
d0 = i0.T
d1 = i1.T
for i in range(n_rot):
r = sp.stats.special_ortho_group.rvs(n_dims).astype(np.float32)
d0r = np.dot(r, d0)
d1r = np.dot(r, d1)
d_r = np.empty_like(d0)
for j in range(n_dims):
lo = min(d0r[j].min(), d1r[j].min())
hi = max(d0r[j].max(), d1r[j].max())
p0r, edges = np.histogram(d0r[j], bins=bins, range=[lo, hi])
p1r, _ = np.histogram(d1r[j], bins=bins, range=[lo, hi])
cp0r = p0r.cumsum().astype(np.float32)
cp0r /= cp0r[-1]
cp1r = p1r.cumsum().astype(np.float32)
cp1r /= cp1r[-1]
f = np.interp(cp0r, cp1r, edges[1:])
d_r[j] = np.interp(d0r[j], edges[1:], f, left=0, right=bins)
d0 = relaxation * np.linalg.solve(r, (d_r - d0r)) + d0
return np.clip ( d0.T.reshape ( (h,w,c) ).astype(i0.dtype) , 0, 1)
def laplacian_matrix(n, m):
mat_D = scipy.sparse.lil_matrix((m, m))
mat_D.setdiag(-1, -1)
mat_D.setdiag(4)
mat_D.setdiag(-1, 1)
mat_A = scipy.sparse.block_diag([mat_D] * n).tolil()
mat_A.setdiag(-1, 1*m)
mat_A.setdiag(-1, -1*m)
return mat_A
def seamless_clone(source, target, mask):
h, w,c = target.shape
result = []
mat_A = laplacian_matrix(h, w)
laplacian = mat_A.tocsc()
mask[0,:] = 1
mask[-1,:] = 1
mask[:,0] = 1
mask[:,-1] = 1
q = np.argwhere(mask==0)
k = q[:,1]+q[:,0]*w
mat_A[k, k] = 1
mat_A[k, k + 1] = 0
mat_A[k, k - 1] = 0
mat_A[k, k + w] = 0
mat_A[k, k - w] = 0
mat_A = mat_A.tocsc()
mask_flat = mask.flatten()
for channel in range(c):
source_flat = source[:, :, channel].flatten()
target_flat = target[:, :, channel].flatten()
mat_b = laplacian.dot(source_flat)*0.75
mat_b[mask_flat==0] = target_flat[mask_flat==0]
x = spsolve(mat_A, mat_b).reshape((h, w))
result.append (x)
return np.clip( np.dstack(result), 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.
This implementation is (loosely) based on to the "Color Transfer
between Images" paper by Reinhard et al., 2001.
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
Returns:
-------
transfer: NumPy array
OpenCV image (w, h, 3) NumPy array (uint8)
"""
# 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)
# 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)
# subtract the means from the target image
(l, a, b) = cv2.split(target)
l -= lMeanTar
a -= aMeanTar
b -= bMeanTar
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
# add in the source mean
l += lMeanSrc
a += aMeanSrc
b += bMeanSrc
# 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):
'''
Matches the colour distribution of the target image to that of the source image
using a linear transform.
Images are expected to be of form (w,h,c) and float in [0,1].
Modes are chol, pca or sym for different choices of basis.
'''
mu_t = target_img.mean(0).mean(0)
t = target_img - mu_t
t = t.transpose(2,0,1).reshape( t.shape[-1],-1)
Ct = t.dot(t.T) / t.shape[1] + eps * np.eye(t.shape[0])
mu_s = source_img.mean(0).mean(0)
s = source_img - mu_s
s = s.transpose(2,0,1).reshape( s.shape[-1],-1)
Cs = s.dot(s.T) / s.shape[1] + eps * np.eye(s.shape[0])
if mode == 'chol':
chol_t = np.linalg.cholesky(Ct)
chol_s = np.linalg.cholesky(Cs)
ts = chol_s.dot(np.linalg.inv(chol_t)).dot(t)
if mode == 'pca':
eva_t, eve_t = np.linalg.eigh(Ct)
Qt = eve_t.dot(np.sqrt(np.diag(eva_t))).dot(eve_t.T)
eva_s, eve_s = np.linalg.eigh(Cs)
Qs = eve_s.dot(np.sqrt(np.diag(eva_s))).dot(eve_s.T)
ts = Qs.dot(np.linalg.inv(Qt)).dot(t)
if mode == 'sym':
eva_t, eve_t = np.linalg.eigh(Ct)
Qt = eve_t.dot(np.sqrt(np.diag(eva_t))).dot(eve_t.T)
Qt_Cs_Qt = Qt.dot(Cs).dot(Qt)
eva_QtCsQt, eve_QtCsQt = np.linalg.eigh(Qt_Cs_Qt)
QtCsQt = eve_QtCsQt.dot(np.sqrt(np.diag(eva_QtCsQt))).dot(eve_QtCsQt.T)
ts = np.linalg.inv(Qt).dot(QtCsQt).dot(np.linalg.inv(Qt)).dot(t)
matched_img = ts.reshape(*target_img.transpose(2,0,1).shape).transpose(1,2,0)
matched_img += mu_s
matched_img[matched_img>1] = 1
matched_img[matched_img<0] = 0
return matched_img
def lab_image_stats(image):
# compute the mean and standard deviation of each channel
(l, a, b) = cv2.split(image)
(lMean, lStd) = (l.mean(), l.std())
(aMean, aStd) = (a.mean(), a.std())
(bMean, bStd) = (b.mean(), b.std())
# return the color statistics
return (lMean, lStd, aMean, aStd, bMean, bStd)
def _scale_array(arr, clip=True):
if clip:
return np.clip(arr, 0, 255)
mn = arr.min()
mx = arr.max()
scale_range = (max([mn, 0]), min([mx, 255]))
if mn < scale_range[0] or mx > scale_range[1]:
return (scale_range[1] - scale_range[0]) * (arr - mn) / (mx - mn) + scale_range[0]
return arr
def channel_hist_match(source, template, hist_match_threshold=255, mask=None):
# Code borrowed from:
# https://stackoverflow.com/questions/32655686/histogram-matching-of-two-images-in-python-2-x
masked_source = source
masked_template = template
if mask is not None:
masked_source = source * mask
masked_template = template * mask
oldshape = source.shape
source = source.ravel()
template = template.ravel()
masked_source = masked_source.ravel()
masked_template = masked_template.ravel()
s_values, bin_idx, s_counts = np.unique(source, return_inverse=True,
return_counts=True)
t_values, t_counts = np.unique(template, return_counts=True)
ms_values, mbin_idx, ms_counts = np.unique(source, return_inverse=True,
return_counts=True)
mt_values, mt_counts = np.unique(template, return_counts=True)
s_quantiles = np.cumsum(s_counts).astype(np.float64)
s_quantiles = hist_match_threshold * s_quantiles / s_quantiles[-1]
t_quantiles = np.cumsum(t_counts).astype(np.float64)
t_quantiles = 255 * t_quantiles / t_quantiles[-1]
interp_t_values = np.interp(s_quantiles, t_quantiles, t_values)
return interp_t_values[bin_idx].reshape(oldshape)
def color_hist_match(src_im, tar_im, hist_match_threshold=255):
h,w,c = src_im.shape
matched_R = channel_hist_match(src_im[:,:,0], tar_im[:,:,0], hist_match_threshold, None)
matched_G = channel_hist_match(src_im[:,:,1], tar_im[:,:,1], hist_match_threshold, None)
matched_B = channel_hist_match(src_im[:,:,2], tar_im[:,:,2], hist_match_threshold, None)
to_stack = (matched_R, matched_G, matched_B)
for i in range(3, c):
to_stack += ( src_im[:,:,i],)
matched = np.stack(to_stack, axis=-1).astype(src_im.dtype)
return matched
def color_transfer_mix(img_src,img_trg):
img_src = (img_src*255.0).astype(np.uint8)
img_trg = (img_trg*255.0).astype(np.uint8)
img_src_lab = cv2.cvtColor(img_src, cv2.COLOR_BGR2LAB)
img_trg_lab = cv2.cvtColor(img_trg, cv2.COLOR_BGR2LAB)
rct_light = np.clip ( linear_color_transfer(img_src_lab[...,0:1].astype(np.float32)/255.0,
img_trg_lab[...,0:1].astype(np.float32)/255.0 )[...,0]*255.0,
0, 255).astype(np.uint8)
img_src_lab[...,0] = (np.ones_like (rct_light)*100).astype(np.uint8)
img_src_lab = cv2.cvtColor(img_src_lab, cv2.COLOR_LAB2BGR)
img_trg_lab[...,0] = (np.ones_like (rct_light)*100).astype(np.uint8)
img_trg_lab = cv2.cvtColor(img_trg_lab, cv2.COLOR_LAB2BGR)
img_rct = color_transfer_sot( img_src_lab.astype(np.float32), img_trg_lab.astype(np.float32) )
img_rct = np.clip(img_rct, 0, 255).astype(np.uint8)
img_rct = cv2.cvtColor(img_rct, cv2.COLOR_BGR2LAB)
img_rct[...,0] = rct_light
img_rct = cv2.cvtColor(img_rct, cv2.COLOR_LAB2BGR)
return (img_rct / 255.0).astype(np.float32)