def func(cls, args, container, watermark, params, default_metrics,
callback):
th = (args[0], args[1], args[2])
max_b = 2**int(args[3])
min_b = 2**int(args[4])
if min_b > max_b:
max_b = min_b
qp = args[5]
sc = args[6]
params = copy(params)
params['homogeneity_threshold'] = th
params['min_block_size'] = min_b
params['max_block_size'] = max_b
params['quant_power'] = qp
params['ch_scale'] = sc
qtar = QtarStego(**params)
maxbpp = len(container.getbands()) * 8
try:
embed_result = qtar.embed(container, watermark)
container_image = embed_result.img_container
stego_image = embed_result.img_stego
watermark = embed_result.img_watermark
extracted_wm = qtar.extract(stego_image, embed_result.key)
cls.eval_callback(callback)
psnr_ = psnr(container_image, stego_image)
bcr_ = bcr(watermark, extracted_wm)
bpp_ = embed_result.bpp
except:
return 1
return sqrt((-1 / psnr_)**2 + (1 - bcr_)**2 + (1 - bpp_ / maxbpp)**2)
def func(cls, offset, container, watermark, params, default_metrics,
callback):
params = copy(params)
params['offset'] = array(offset).astype(int)
qtar = QtarStego(**params)
embed_result = qtar.embed(container, watermark)
cls.eval_callback(callback)
watermark = embed_result.img_watermark
extracted_wm = qtar.extract(embed_result.img_stego, embed_result.key)
return -bcr(watermark, extracted_wm)
def func(cls, threshold, container, watermark, params, default_metrics,
callback):
params = copy(params)
params['homogeneity_threshold'] = threshold
qtar = QtarStego(**params)
embed_result = qtar.embed(container, watermark)
cls.eval_callback(callback)
watermark = embed_result.img_watermark
extracted_wm = qtar.extract(embed_result.img_stego, embed_result.key)
return -bcr(watermark, extracted_wm)
def extract(params):
key = Key.open(params['key'])
stego_image = Image.open(params['stego'])
with benchmark("extracted in"):
secret_image = QtarStego.extract(stego_image, key)
if params['wm_path']:
si_path = params['wm_path']
else:
stego_image_file_name = extract_filename(params['stego'])
si_path = 'extracted_from_%s.png' % stego_image_file_name
save_file(secret_image, si_path)
def func(cls, args, container, watermark, params, default_metrics,
callback):
def_psnr_c = default_metrics['container psnr']
def_psnr_w = default_metrics['watermark psnr']
def_bpp = default_metrics['container bpp']
new_params = {
'homogeneity_threshold': (args[0], args[1], args[2]),
'min_block_size': 2**int(args[3]),
'cf_grid_size': int(args[4]),
'wmdct_block_size': 2**int(args[5]),
'offset': (int(args[6]), int(args[7]))
}
params = copy(params)
params.update(new_params)
qtar = QtarStego(**params)
try:
embed_result = qtar.embed(container, watermark)
wm_extracted = qtar.extract(embed_result.img_stego,
embed_result.key)
except Exception as e:
cls.eval_callback(callback,
error=e,
new_params=new_params,
f=cls.best_one)
return 0
psnr_c = psnr(embed_result.img_container, embed_result.img_stego)
psnr_w = psnr(embed_result.img_watermark, wm_extracted)
bpp_ = embed_result.bpp
func = -((psnr_c - def_psnr_c) / def_psnr_c +
(bpp_ - def_bpp) / def_bpp +
(psnr_w - def_psnr_w) / def_psnr_w)
if psnr_c < def_psnr_c or bpp_ < def_bpp or psnr_w < def_psnr_w:
func = 0
if func < cls.best_one:
cls.best_one = func
cls.eval_callback(callback, f=cls.best_one)
return func
def func(cls, args, container, watermark, params, default_metrics,
callback):
max_b = 2**int(args[0])
qp = args[1]
sc = args[2]
params = copy(params)
params['max_block_size'] = max_b
params['quant_power'] = qp
params['ch_scale'] = sc
qtar = QtarStego(**params)
embed_result = qtar.embed(container, watermark)
cls.eval_callback(callback)
watermark = embed_result.img_watermark
extracted_wm = qtar.extract(embed_result.img_stego, embed_result.key)
return -bcr(watermark, extracted_wm)
def embed(params, filter_=None):
container = Image.open(params['container'])
if 'container_size' in params and params['container_size']:
container = container.resize(params['container_size'], Image.BILINEAR)
watermark = Image.open(params['watermark'])
if 'watermark_size' in params and params['watermark_size']:
watermark = watermark.resize(params['watermark_size'], Image.BILINEAR)
qtar = QtarStego(**params)
embed_result = qtar.embed(container, watermark)
container = embed_result.img_container
stego = embed_result.img_stego
wm = embed_result.img_watermark
key = embed_result.key
bpp_ = embed_result.bpp
psnr_container = psnr(container, stego)
ssim_container = ssim(container, stego)
if filter_ is not None:
stego = filter_(stego)
extracted_wm = qtar.extract(stego, key)
bcr_wm = bcr(wm, extracted_wm)
psnr_wm = psnr(wm, extracted_wm)
ssim_wm = ssim(wm, extracted_wm)
return {
"stego img": stego,
"extracted wm": extracted_wm,
"container psnr": psnr_container,
"container ssim": ssim_container,
"watermark psnr": psnr_wm,
"watermark ssim": ssim_wm,
"watermark bcr": bcr_wm,
"container bpp": bpp_,
"key size": key.size
}
def func(cls, args, container, watermark, params, default_metrics,
callback):
th = (args[0], args[1], args[2])
x = int(args[3])
y = int(args[4])
qp = args[5]
sc = args[6]
params = copy(params)
params['homogeneity_threshold'] = th
params['offset'] = (x, y)
params['quant_power'] = qp
params['ch_scale'] = sc
qtar = QtarStego(**params)
maxbpp = len(container.getbands()) * 8
psnr_w = 0.999
bcr_w = 0.0005
bpp_w = 0.0005
try:
embed_result = qtar.embed(container, watermark)
container_image = embed_result.img_container
stego_image = embed_result.img_stego
watermark = embed_result.img_watermark
extracted_wm = qtar.extract(stego_image, embed_result.key)
cls.eval_callback(callback)
psnr_ = psnr(container_image, stego_image)
bcr_ = bcr(watermark, extracted_wm)
bpp_ = embed_result.bpp
except:
return 1
return sqrt(psnr_w * (-1 / psnr_)**2 + bcr_w * (1 - bcr_)**2 + bpp_w *
(1 - bpp_ / maxbpp)**2)
def test(params):
container = Image.open(params['container'])
if params['container_size']:
container = container.resize(params['container_size'], Image.BILINEAR)
watermark = Image.open(params['watermark'])
if params['watermark_size']:
watermark = watermark.resize(params['watermark_size'], Image.BILINEAR)
embedding_info = EMBEDDING_INFO_TEMPLATE.format(**params)
print(embedding_info)
qtar = QtarStego(**params)
try:
with benchmark("embedded in "):
embed_result = qtar.embed(container, watermark, stages=True)
except NoSpaceError as e:
print(e)
return {
"container psnr": 0,
"container ssim": 0,
"watermark psnr": 0,
"watermark ssim": 0,
"watermark bcr": 0,
"container bpp": 0,
"key size": 0
}
container = embed_result.img_container
stego = embed_result.img_stego
wm = embed_result.img_watermark
key = embed_result.key
bpp_ = embed_result.bpp
psnr_container = psnr(container, stego)
ssim_container = ssim(container, stego)
if 'ss' in params and params['ss']:
save_stages(
embed_result.stages_imgs,
STAMP_TEMPLATE.format(psnr=psnr_container,
ssim=ssim_container,
bpp=bpp_) if params['st'] else None)
if 'key' in params and params['key']:
save_file(key, params['key'])
key = Key.open(params['key'])
key_info = KEY_INFO_TEMPLATE.format(key=key)
print(key_info)
with benchmark("extracted in"):
extract_stages_imgs = qtar.extract(stego, key, stages=True)
extracted_wm = extract_stages_imgs['9-extracted_watermark']
if 'ss' in params and params['ss']:
save_stages(extract_stages_imgs)
bcr_wm = bcr(wm, extracted_wm)
psnr_wm = psnr(wm, extracted_wm)
ssim_wm = ssim(wm, extracted_wm)
metrics_info = METRICS_INFO_TEMPLATE.format(psnr_container=psnr_container,
ssim_container=ssim_container,
psnr_wm=psnr_wm,
ssim_wm=ssim_wm,
bpp=bpp_,
bcr=bcr_wm,
width=wm.size[0],
height=wm.size[1])
print(metrics_info)
print("_" * 40 + '\n')
return {
"container psnr": psnr_container,
"container ssim": ssim_container,
"watermark psnr": psnr_wm,
"watermark ssim": ssim_wm,
"watermark bcr": bcr_wm,
"container bpp": bpp_,
"key size": key.size
}