def _get_previews(self):
"""Extract previews."""
if len(self.metadata.get_preview_properties()) > 0:
# Fetched previews key.
self.results["preview"] = []
for preview in self.metadata.get_preview_properties():
p = AutoVivification()
p["mime_type"] = preview.get_mime_type()
p["size"] = len(self.metadata.get_preview_image(preview).get_data())
p["ext"] = preview.get_extension()
p["dimensions"] = [preview.get_width(), preview.get_height()]
# Resize if needed, and store.
try:
img = utils.str2image(self.metadata.get_preview_image(preview).get_data())
if preview.get_width() > 256 or preview.get_height() > 160:
p["original_file"] = save_file(utils.image2str(img), content_type="image/jpeg")
img.thumbnail([256, 160], Image.ANTIALIAS)
p["file"] = save_file(utils.image2str(img), content_type="image/jpeg")
except Exception as e:
logger.warning("Error reading preview: {0}".format(e))
continue
finally:
# Save.
self.results["preview"].append(p)
def _get_previews(self):
"""Extract previews."""
if len(self.metadata.get_preview_properties()) > 0:
# Fetched previews key.
self.results["preview"] = []
for preview in self.metadata.get_preview_properties():
p = AutoVivification()
p["mime_type"] = preview.get_mime_type()
p["size"] = len(
self.metadata.get_preview_image(preview).get_data())
p["ext"] = preview.get_extension()
p["dimensions"] = [preview.get_width(), preview.get_height()]
# Resize if needed, and store.
try:
img = utils.str2image(
self.metadata.get_preview_image(preview).get_data())
if preview.get_width() > 256 or preview.get_height() > 160:
p["original_file"] = save_file(
utils.image2str(img), content_type="image/jpeg")
img.thumbnail([256, 160], Image.ANTIALIAS)
p["file"] = save_file(utils.image2str(img),
content_type="image/jpeg")
except Exception as e:
logger.warning("Error reading preview: {0}".format(e))
continue
finally:
# Save.
self.results["preview"].append(p)
def run(self):
"""Run data analysis."""
# Create temporary file.
handle, resaved = tempfile.mkstemp()
# Open file and resave it.
try:
im = Image.open(self.file_path)
im.save(resaved, "JPEG", quality=95)
resaved_im = Image.open(resaved)
except IOError as e:
logger.warning("ELA error opening image: {0}".format(e))
return
finally:
os.close(handle)
os.remove(resaved)
# Trick to convert images like PNG to a format comparable with JPEG.
if im.mode != "RGB":
im = im.convert("RGB")
# Create ELA image.
try:
ela_im = ImageChops.difference(im, resaved_im)
except Exception as e:
logger.warning("Unable to calculate ELA difference: {0}".format(e))
return
# Calculate difference
extrema = ela_im.getextrema()
max_diff = max([ex[1] for ex in extrema])
if not max_diff:
return
scale = 255.0 / max_diff
ela_im = ImageEnhance.Brightness(ela_im).enhance(scale)
self.results["max_difference"] = max([ex[1] for ex in extrema])
# Resize image if it's too big.
width, height = ela_im.size
if width > 1800:
ela_im.thumbnail([1800, 1800], Image.ANTIALIAS)
# Save image.
try:
img = utils.image2str(ela_im)
self.results["ela_image"] = save_file(img,
content_type="image/jpeg")
except Exception as e:
logger.warning("ELA error saving image: {0}".format(e))
finally:
return self.results
def run(self):
"""Run data analysis."""
# Create temporary file.
handle, resaved = tempfile.mkstemp()
# Open file and resave it.
try:
im = Image.open(self.file_path)
im.save(resaved, "JPEG", quality=95)
resaved_im = Image.open(resaved)
except IOError as e:
logger.warning("ELA error opening image: {0}".format(e))
return
finally:
os.close(handle)
os.remove(resaved)
# Trick to convert images like PNG to a format comparable with JPEG.
if im.mode != "RGB":
im = im.convert("RGB")
# Create ELA image.
try:
ela_im = ImageChops.difference(im, resaved_im)
except Exception as e:
logger.warning("Unable to calculate ELA difference: {0}".format(e))
return
# Calculate difference
extrema = ela_im.getextrema()
max_diff = max([ex[1] for ex in extrema])
if not max_diff:
return
scale = 255.0 / max_diff
ela_im = ImageEnhance.Brightness(ela_im).enhance(scale)
self.results["max_difference"] = max([ex[1] for ex in extrema])
# Resize image if it's too big.
width, height = ela_im.size
if width > 1800:
ela_im.thumbnail([1800, 1800], Image.ANTIALIAS)
# Save image.
try:
img = utils.image2str(ela_im)
self.results["ela_image"] = save_file(img, content_type="image/jpeg")
except Exception as e:
logger.warning("ELA error saving image: {0}".format(e))
finally:
return self.results
