def image_to_jpeg_wand(self,
jpeg: typing.Union[str, typing.IO[bytes]],
preview_dims: ImgDims = None) -> BytesIO:
"""
for jpeg, gif and bmp
:param jpeg:
:param size:
:return:
"""
self.logger.info("Converting image to jpeg using wand")
with WImage(file=jpeg, background=Color("white")) as image:
preview_dims = ImgDims(width=preview_dims.width,
height=preview_dims.height)
resize_dim = compute_resize_dims(dims_in=ImgDims(
width=image.size[0], height=image.size[1]),
dims_out=preview_dims)
image.resize(resize_dim.width, resize_dim.height)
# INFO - jumenzel - 2019-03-12 - remove metadata, color-profiles from this image.
image.strip()
content_as_bytes = image.make_blob("jpeg")
output = BytesIO()
output.write(content_as_bytes)
output.seek(0, 0)
return output
def test_compute_resize_dims_right_limits():
dims_in = ImgDims(520, 206) # vertical
dims_out = ImgDims(512, 256) # horizontal
dims_resize = compute_resize_dims(dims_in, dims_out)
assert dims_resize.width == 512
assert dims_resize.height == 203
def image_to_jpeg_pillow(
self,
png: typing.Union[str, typing.IO[bytes]],
preview_dims: ImgDims
) -> BytesIO:
self.logger.info('Converting image to jpeg using Pillow')
with Image.open(png) as image:
resize_dim = compute_resize_dims(
dims_in=ImgDims(width=image.size[0], height=image.size[1]),
dims_out=preview_dims
)
image = image.resize((resize_dim.width, resize_dim.height))
output_image = Image.new(
'RGB',
(resize_dim.width, resize_dim.height),
(255, 255, 255)
)
try:
output_image.paste(image, (0, 0), image)
except ValueError:
self.logger.warning(
'Failed the transparency mask superposition. '
'Maybe your image does not contain a transparency mask')
output_image.paste(image)
output = BytesIO()
output_image.save(output, 'jpeg')
output.seek(0, 0)
return output
def _convert_image(self, file_path: str, preview_dims: ImgDims) -> Image:
"""
refer: https://legacy.imagemagick.org/Usage/thumbnails/
like cmd: convert -layers merge -background white -thumbnail widthxheight \
-auto-orient -quality 85 -interlace plane input.jpeg output.jpeg
"""
img = Image(filename=file_path)
resize_dim = compute_resize_dims(dims_in=ImgDims(width=img.width,
height=img.height),
dims_out=preview_dims)
img.auto_orient()
img.iterator_reset()
img.background_color = Color("white")
img.merge_layers("merge")
if self.progressive:
img.interlace_scheme = "plane"
img.compression_quality = self.quality
img.thumbnail(resize_dim.width, resize_dim.height)
return img
def test_compute_resize_dims_different_ratio():
dims_in = ImgDims(100, 50) # horizontal
dims_out = ImgDims(200, 400) # vertical
dims_resize = compute_resize_dims(dims_in, dims_out)
assert dims_resize.width == 200
assert dims_resize.height == 100
def test_compute_resize_dims_different_ratio_inverted():
dims_in = ImgDims(198, 600) # vertical
dims_out = ImgDims(400, 100) # horizontal
dims_resize = compute_resize_dims(dims_in, dims_out)
assert dims_resize.width == 33
assert dims_resize.height == 100
def test_compute_resize_dims_same_format():
dims_in = ImgDims(100, 50)
dims_out = ImgDims(90, 30)
dims_resize = compute_resize_dims(dims_in, dims_out)
assert dims_resize.width == 60
assert dims_resize.height == 30
def test_compute_resize_dims_same_ratio():
dims_in = ImgDims(100, 50)
dims_out = ImgDims(200, 100)
dims_resize = compute_resize_dims(dims_in, dims_out)
assert dims_resize.width == 200
assert dims_resize.height == 100
def image_to_jpeg_wand(self,
jpeg: typing.Union[str, typing.IO[bytes]],
preview_dims: ImgDims = None) -> BytesIO:
'''
for jpeg, gif and bmp
:param jpeg:
:param size:
:return:
'''
logging.info('Converting image to jpeg using wand')
with WImage(file=jpeg, background=Color('white')) as image:
preview_dims = ImgDims(width=preview_dims.width,
height=preview_dims.height)
resize_dim = compute_resize_dims(dims_in=ImgDims(
width=image.size[0], height=image.size[1]),
dims_out=preview_dims)
image.resize(resize_dim.width, resize_dim.height)
content_as_bytes = image.make_blob('jpeg')
output = BytesIO()
output.write(content_as_bytes)
output.seek(0, 0)
return output
def test_compute_resize_dims_same_format():
dims_in = ImgDims(100, 50)
dims_out = ImgDims(90, 30)
builder = ImagePreviewBuilderWand()
dims_resize = compute_resize_dims(dims_in, dims_out)
assert dims_resize.width == 60
assert dims_resize.height == 30
def test_compute_resize_dims_same_ratio():
dims_in = ImgDims(100, 50)
dims_out = ImgDims(200, 100)
builder = ImagePreviewBuilderWand()
dims_resize = compute_resize_dims(dims_in, dims_out)
assert dims_resize.width == 200
assert dims_resize.height == 100
def convert_pdf_to_jpeg(pdf: typing.Union[str, typing.IO[bytes]],
preview_size: ImgDims) -> BytesIO:
pdf = pdf.read()
images = convert_from_bytes(pdf)
output = BytesIO()
for image in images:
resize_dims = compute_resize_dims(ImgDims(image.width, image.height),
preview_size)
resized = image.resize((resize_dims.width, resize_dims.height),
resample=True)
resized.save(output, format="JPEG")
output.seek(0, 0)
return output
def convert_pdf_to_jpeg(pdf, preview_size):
with WImage(file=pdf) as img:
# HACK - D.A. - 2017-08-01
# The following 2 lines avoid black background in case of transparent
# objects found on the page. As we save to JPEG, this is not a problem
img.background_color = Color('white')
img.alpha_channel = 'remove'
resize_dims = compute_resize_dims(ImgDims(img.width, img.height),
preview_size)
img.resize(resize_dims.width, resize_dims.height)
content_as_bytes = img.make_blob('jpeg')
output = BytesIO()
output.write(content_as_bytes)
output.seek(0, 0)
return output
def image_to_jpeg_pillow(self, png: typing.Union[str, typing.IO[bytes]],
preview_dims: ImgDims) -> BytesIO:
self.logger.info("Converting image to jpeg using Pillow")
with Image.open(png) as image:
resize_dim = compute_resize_dims(dims_in=ImgDims(
width=image.size[0], height=image.size[1]),
dims_out=preview_dims)
output = BytesIO()
image = image.resize((resize_dim.width, resize_dim.height),
resample=self.resample_filter_algorithm)
image_converter = PillowImageConvertStrategyFactory(
self.logger).get_strategy(image)
return image_converter.save(
image,
output,
optimize=self.optimize,
progressive=self.progressive,
quality=self.quality,
)
def test_png_to_jpeg_with_background_white() -> None:
image_file_path = os.path.join(CURRENT_DIR, "the_png.png")
to_size = ImgDims(width=512, height=256)
with Image(filename=image_file_path) as input_img:
input_size = ImgDims(width=input_img.width, height=input_img.height)
expected_size = compute_resize_dims(input_size, to_size)
manager = PreviewManager(cache_folder_path=CACHE_DIR, create_folder=True)
assert manager.has_jpeg_preview(file_path=image_file_path) is True
path_to_file = manager.get_jpeg_preview(
file_path=image_file_path, width=to_size.width, height=to_size.height, force=True
)
assert os.path.exists(path_to_file) is True
assert os.path.getsize(path_to_file) > 0
assert re.match(test_utils.CACHE_FILE_PATH_PATTERN__JPEG, path_to_file)
with Image(filename=path_to_file) as output_img:
assert output_img.width == expected_size.width
assert output_img.height == expected_size.height
assert nearest_colour_white(output_img[5][5])
