def shear(img, x=False, y=False):
"""Apply vertical or horizontal shear effects (or both).
We achieve this by applying a simple affine transformation.
The new image size calculation is a bit off if you apply both horizontal
and vertical shear at the same time.
"""
# If true, then this is a no-op so let's just not bother
if not x and not y:
return img
width, height = img.size
x_shift = abs(x) * height
y_shift = abs(y) * width
# If we're applying a positive shear in either direction, we must also
# apply a translation (by setting the 'c' and 'f' parameters passed to
# PIL) so the resulting image data ends up entirely inside the bounds of
# the resized image.
# If we don't do this we'll end up with an output image of the correct
# size but leaving parts of the original chopped off.
return img.transform(
(width + px(x_shift), height + px(y_shift)),
Image.AFFINE,
(
1, x, -x_shift if x > 0 else 0,
y, 1, -y_shift if y > 0 else 0,
),
Image.BICUBIC,
)
def shear(img, x=False, y=False):
"""Apply vertical or horizontal shear effects (or both).
We achieve this by applying a simple affine transformation.
The new image size calculation is a bit off if you apply both horizontal
and vertical shear at the same time.
"""
# If true, then this is a no-op so let's just not bother
if not x and not y:
return img
width, height = img.size
x_shift = abs(x) * height
y_shift = abs(y) * width
# If we're applying a positive shear in either direction, we must also
# apply a translation (by setting the 'c' and 'f' parameters passed to
# PIL) so the resulting image data ends up entirely inside the bounds of
# the resized image.
# If we don't do this we'll end up with an output image of the correct
# size but leaving parts of the original chopped off.
return img.transform(
(width + px(x_shift), height + px(y_shift)),
Image.AFFINE,
(
1,
x,
-x_shift if x > 0 else 0,
y,
1,
-y_shift if y > 0 else 0,
),
Image.BICUBIC,
)
def assemble(fname, **kwargs):
"""Slice the given file name into page thumbnails and arrange as a preview.
The only required information is the path to the input file, all other
parameters have sensible defaults (see ``bocho.DEFAULTS``).
Per-page PNG files can optionally be re-used between runs, but the output
file must be removed or we will raise an exception unless you pass
``delete=True``.
Args:
fname (str): The input file name
Kwargs:
pages (list): Pages to use from the source file
width (int): pixel width of the output image
height (int): pixel height of the output image
resolution (int): DPI used in converting PDF pages to PNG
angle (int): rotation from vertical (degrees between -90 and 90)
offset_x (int): horizontal pixel offset for shifting the output
offset_y (int): vertical pixel offset for shifting the output
spacing_x (int): horizontal pixel spacing between pages
spacing_y (int): vertical pixel spacing between pages
zoom: (tuple) zoom factor to be applied after arranging pages
border (int): pixel width of the page border to be added
colour (str): colour of the page border
shadow (bool): soften the border for a 'shadow' effect (slow)
shear_x (float): optionally apply a horizontal shear effect
shear_y (float): optionally apply a vertical shear effect
reverse (bool): stack the pages right to left
reuse (bool): re-use the per-page PNG files between runs
delete (bool): delete the output file before running
use_convert (bool): optionally use 'convert' rather than Wand
config (str): custom path to config.ini
preset (str): use the named preset to override defaults
parallel (int): use multiprocessing to apply the borders & shadow
Returns:
string. The path to the output file
"""
global VERBOSE
cfg = None
preset = kwargs.get("preset")
cfg_fname = kwargs.get("config")
if preset:
msg = 'loading custom defaults from preset "%s"' % preset
if cfg_fname:
msg = "%s from %s" % (msg, cfg_fname)
print(msg)
cfg = config.load(cfg_fname)
def _kwarg_or_default(name):
result = kwargs.get(name)
if result is None:
if cfg and preset and cfg.has_section(preset):
if cfg.has_option(preset, name):
return cfg.getval(preset, name)
result = DEFAULTS.get(name)
return result
VERBOSE = _kwarg_or_default("verbose")
offset_x = _kwarg_or_default("offset_x")
offset_y = _kwarg_or_default("offset_y")
spacing_x = _kwarg_or_default("spacing_x")
spacing_y = _kwarg_or_default("spacing_y")
pages = _kwarg_or_default("pages")
width = _kwarg_or_default("width")
height = _kwarg_or_default("height")
resolution = _kwarg_or_default("resolution")
angle = _kwarg_or_default("angle")
zoom = _kwarg_or_default("zoom")
border = _kwarg_or_default("border")
colour = _kwarg_or_default("colour")
shadow = _kwarg_or_default("shadow")
shear_x = _kwarg_or_default("shear_x")
shear_y = _kwarg_or_default("shear_y")
reverse = _kwarg_or_default("reverse")
reuse = _kwarg_or_default("reuse")
delete = _kwarg_or_default("delete")
use_convert = _kwarg_or_default("use_convert")
parallel = _kwarg_or_default("parallel")
if not use_convert and not WAND_AVAILABLE:
log("Wand is not installed, so using `convert` directly.")
use_convert = True
assert -90 <= angle <= 90
angle = math.radians(angle)
file_path = "%s-bocho-%sx%s.png" % (fname[:-4], width, height)
if os.path.exists(file_path):
if not delete:
raise Exception("%s already exists, not overwriting" % file_path)
else:
log("removing output file before running: %s" % file_path)
os.remove(file_path)
n = len(pages)
if angle:
spacing_y = spacing_x * math.cos(angle) + spacing_y
spacing_x = abs(spacing_y / math.tan(angle))
log("spacing: %s" % str((spacing_x, spacing_y)))
out_path = "%s-page.png" % fname[:-4]
tmp_image_names = ["%s-%d.png" % (out_path[:-4], p - 1) for p in pages]
if all(map(os.path.exists, tmp_image_names)) and reuse:
log("re-using existing individual page PNGs")
else:
if any(map(os.path.exists, tmp_image_names)):
if delete:
for path in tmp_image_names:
if os.path.exists(path):
os.remove(path)
else:
raise Exception("Not overwriting page PNG files, please delete: %s" % tmp_image_names)
log("converting input PDF to individual page PDFs")
slice_pages(fname, pages, out_path, resolution, use_convert)
page_0 = Image.open(tmp_image_names[0])
log("page size of sliced pages: %dx%d" % page_0.size)
slice_size = page_0.size
scale = slice_size[1] / height
log("input to output scale: %0.2f" % scale)
spacing_x = px(spacing_x * scale)
spacing_y = px(spacing_y * scale)
log("spacing after scaling up: %dx%d" % (spacing_x, spacing_y))
# We make a bit of an assumption here that the output image is going to be
# wider than it is tall and that by default we want the sliced pages to fit
# vertically (assuming no rotation) and that the spacing will fill the
# image horizontally.
page_width = px(slice_size[0])
page_height = px(slice_size[1])
log("page size before resizing down: %dx%d" % (page_width, page_height))
# If there's no angle specified then all the y coords will be zero and the
# x coords will be a multiple of the provided spacing
x_coords = list(map(int, [i * spacing_x for i in range(n)]))
y_coords = list(map(int, [i * spacing_y for i in range(n)]))
if angle < 0:
y_coords.sort(reverse=True)
size = (px(width * scale), px(height * scale))
log("output size before resizing: %dx%d" % size)
if angle != 0:
# If we're rotating the pages, we stack them up with appropriate
# horizontal and vertical offsets first, then we rotate the result.
# Because of this, we must expand the output image to be large enough
# to fit the unrotated stack. The rotation operation below will expand
# the output image enough so everything still fits, but this bit we
# need to figure out for ourselves in advance.
size = (page_width + max(x_coords), page_height + max(y_coords))
log("output size before rotate + crop: %dx%d" % size)
outfile = Image.new("RGB", size)
log("outfile dimensions: %dx%d" % outfile.size)
border = partial(_add_border, width=border, shadow=shadow, fill=colour)
# _add_border returns a path to a temporary file containing the page plus
# border
if parallel and parallel > 1:
log("applying borders with %d processes" % parallel)
p = Pool(parallel)
mapper = p.imap
else:
log("applying borders sequentially")
mapper = imap
iterable = mapper(border, reversed(tmp_image_names))
for x, fpath in enumerate(iterable, 1):
# Draw lines down the right and bottom edges of each page to provide
# visual separation. Cheap drop-shadow basically.
img = Image.open(fpath)
if reverse:
coords = (x_coords[x - 1], y_coords[x - 1])
else:
coords = (x_coords[-x], y_coords[-x])
# If we don't use img as the mask, PIL drops the alpha channel
log("placing page %d at %s" % (pages[-x], coords))
outfile.paste(img, coords, img)
os.remove(fpath)
del page_0, img
if reuse:
log("leaving individual page PNG files in place")
else:
for tmp in tmp_image_names:
log("deleting temporary file: %s" % tmp)
os.remove(tmp)
if shear_x or shear_y:
log("applying shear effect")
outfile = transforms.shear(outfile, shear_x, shear_y)
log("output size after transformation: %dx%d" % outfile.size)
if angle != 0:
log("rotating image by %0.2f degrees" % math.degrees(angle))
outfile = outfile.rotate(math.degrees(angle), Image.BICUBIC, True)
log("output size before cropping: %dx%d" % outfile.size)
# Cropping is simply a case of positioning a rectangle of the desired
# dimensions about the center of the image.
delta = list(map(px, ((width * scale) / zoom, (height * scale) / zoom)))
left = max(0, (outfile.size[0] - delta[0]) / 2 - (offset_x * scale))
top = max(0, (outfile.size[1] - delta[1]) / 2 - (offset_y * scale))
box = (left, top, left + delta[0], top + delta[1])
outfile = outfile.crop(box)
log("crop box: (%d, %d, %d, %d)" % box)
# Finally, resize the output to the desired size and save.
outfile = outfile.resize((width, height), Image.ANTIALIAS)
log("output saved with dimensions: %dx%d" % outfile.size)
outfile.save(file_path)
return file_path
def assemble(fname, **kwargs):
"""Slice the given file name into page thumbnails and arrange as a preview.
The only required information is the path to the input file, all other
parameters have sensible defaults (see ``bocho.DEFAULTS``).
Per-page PNG files can optionally be re-used between runs, but the output
file must be removed or we will raise an exception unless you pass
``delete=True``.
Args:
fname (str): The input file name
Kwargs:
pages (list): Pages to use from the source file
width (int): pixel width of the output image
height (int): pixel height of the output image
resolution (int): DPI used in converting PDF pages to PNG
angle (int): rotation from vertical (degrees between -90 and 90)
offset_x (int): horizontal pixel offset for shifting the output
offset_y (int): vertical pixel offset for shifting the output
spacing_x (int): horizontal pixel spacing between pages
spacing_y (int): vertical pixel spacing between pages
zoom: (tuple) zoom factor to be applied after arranging pages
border (int): pixel width of the page border to be added
colour (str): colour of the page border
shadow (bool): soften the border for a 'shadow' effect (slow)
shear_x (float): optionally apply a horizontal shear effect
shear_y (float): optionally apply a vertical shear effect
reverse (bool): stack the pages right to left
reuse (bool): re-use the per-page PNG files between runs
delete (bool): delete the output file before running
use_convert (bool): optionally use 'convert' rather than Wand
config (str): custom path to config.ini
preset (str): use the named preset to override defaults
parallel (int): use multiprocessing to apply the borders & shadow
Returns:
string. The path to the output file
"""
global VERBOSE
cfg = None
preset = kwargs.get('preset')
cfg_fname = kwargs.get('config')
if preset:
msg = 'loading custom defaults from preset "%s"' % preset
if cfg_fname:
msg = '%s from %s' % (msg, cfg_fname)
print(msg)
cfg = config.load(cfg_fname)
def _kwarg_or_default(name):
result = kwargs.get(name)
if result is None:
if cfg and preset and cfg.has_section(preset):
if cfg.has_option(preset, name):
return cfg.getval(preset, name)
result = DEFAULTS.get(name)
return result
VERBOSE = _kwarg_or_default('verbose')
offset_x = _kwarg_or_default('offset_x')
offset_y = _kwarg_or_default('offset_y')
spacing_x = _kwarg_or_default('spacing_x')
spacing_y = _kwarg_or_default('spacing_y')
pages = _kwarg_or_default('pages')
width = _kwarg_or_default('width')
height = _kwarg_or_default('height')
resolution = _kwarg_or_default('resolution')
angle = _kwarg_or_default('angle')
zoom = _kwarg_or_default('zoom')
border = _kwarg_or_default('border')
colour = _kwarg_or_default('colour')
shadow = _kwarg_or_default('shadow')
shear_x = _kwarg_or_default('shear_x')
shear_y = _kwarg_or_default('shear_y')
reverse = _kwarg_or_default('reverse')
reuse = _kwarg_or_default('reuse')
delete = _kwarg_or_default('delete')
use_convert = _kwarg_or_default('use_convert')
parallel = _kwarg_or_default('parallel')
if not use_convert and not WAND_AVAILABLE:
log('Wand is not installed, so using `convert` directly.')
use_convert = True
assert -90 <= angle <= 90
angle = math.radians(angle)
file_path = '%s-bocho-%sx%s.png' % (fname[:-4], width, height)
if os.path.exists(file_path):
if not delete:
raise Exception("%s already exists, not overwriting" % file_path)
else:
log('removing output file before running: %s' % file_path)
os.remove(file_path)
n = len(pages)
if angle:
spacing_y = spacing_x * math.cos(angle) + spacing_y
spacing_x = abs(spacing_y / math.tan(angle))
log('spacing: %s' % str((spacing_x, spacing_y)))
out_path = '%s-page.png' % fname[:-4]
tmp_image_names = ['%s-%d.png' % (out_path[:-4], p - 1) for p in pages]
if all(map(os.path.exists, tmp_image_names)) and reuse:
log('re-using existing individual page PNGs')
else:
if any(map(os.path.exists, tmp_image_names)):
if delete:
for path in tmp_image_names:
if os.path.exists(path):
os.remove(path)
else:
raise Exception(
'Not overwriting page PNG files, please delete: %s' %
tmp_image_names, )
log('converting input PDF to individual page PDFs')
slice_pages(fname, pages, out_path, resolution, use_convert)
page_0 = Image.open(tmp_image_names[0])
log('page size of sliced pages: %dx%d' % page_0.size)
slice_size = page_0.size
scale = slice_size[1] / height
log('input to output scale: %0.2f' % scale)
spacing_x = px(spacing_x * scale)
spacing_y = px(spacing_y * scale)
log('spacing after scaling up: %dx%d' % (spacing_x, spacing_y))
# We make a bit of an assumption here that the output image is going to be
# wider than it is tall and that by default we want the sliced pages to fit
# vertically (assuming no rotation) and that the spacing will fill the
# image horizontally.
page_width = px(slice_size[0])
page_height = px(slice_size[1])
log('page size before resizing down: %dx%d' % (page_width, page_height))
# If there's no angle specified then all the y coords will be zero and the
# x coords will be a multiple of the provided spacing
x_coords = list(map(int, [i * spacing_x for i in range(n)]))
y_coords = list(map(int, [i * spacing_y for i in range(n)]))
if angle < 0:
y_coords.sort(reverse=True)
size = (px(width * scale), px(height * scale))
log('output size before resizing: %dx%d' % size)
if angle != 0:
# If we're rotating the pages, we stack them up with appropriate
# horizontal and vertical offsets first, then we rotate the result.
# Because of this, we must expand the output image to be large enough
# to fit the unrotated stack. The rotation operation below will expand
# the output image enough so everything still fits, but this bit we
# need to figure out for ourselves in advance.
size = (page_width + max(x_coords), page_height + max(y_coords))
log('output size before rotate + crop: %dx%d' % size)
outfile = Image.new('RGB', size)
log('outfile dimensions: %dx%d' % outfile.size)
border = partial(_add_border, width=border, shadow=shadow, fill=colour)
# _add_border returns a path to a temporary file containing the page plus
# border
if parallel and parallel > 1:
log('applying borders with %d processes' % parallel)
p = Pool(parallel)
mapper = p.imap
else:
log('applying borders sequentially')
mapper = imap
iterable = mapper(border, reversed(tmp_image_names))
for x, fpath in enumerate(iterable, 1):
# Draw lines down the right and bottom edges of each page to provide
# visual separation. Cheap drop-shadow basically.
img = Image.open(fpath)
if reverse:
coords = (x_coords[x - 1], y_coords[x - 1])
else:
coords = (x_coords[-x], y_coords[-x])
# If we don't use img as the mask, PIL drops the alpha channel
log('placing page %d at %s' % (pages[-x], coords))
outfile.paste(img, coords, img)
os.remove(fpath)
del page_0, img
if reuse:
log('leaving individual page PNG files in place')
else:
for tmp in tmp_image_names:
log('deleting temporary file: %s' % tmp)
os.remove(tmp)
if shear_x or shear_y:
log('applying shear effect')
outfile = transforms.shear(outfile, shear_x, shear_y)
log('output size after transformation: %dx%d' % outfile.size)
if angle != 0:
log('rotating image by %0.2f degrees' % math.degrees(angle))
outfile = outfile.rotate(math.degrees(angle), Image.BICUBIC, True)
log('output size before cropping: %dx%d' % outfile.size)
# Cropping is simply a case of positioning a rectangle of the desired
# dimensions about the center of the image.
delta = list(map(px, ((width * scale) / zoom, (height * scale) / zoom)))
left = max(0, (outfile.size[0] - delta[0]) / 2 - (offset_x * scale))
top = max(0, (outfile.size[1] - delta[1]) / 2 - (offset_y * scale))
box = (left, top, left + delta[0], top + delta[1])
outfile = outfile.crop(box)
log('crop box: (%d, %d, %d, %d)' % box)
# Finally, resize the output to the desired size and save.
outfile = outfile.resize((width, height), Image.ANTIALIAS)
log('output saved with dimensions: %dx%d' % outfile.size)
outfile.save(file_path)
return file_path
def test_px(self):
self.assertEqual(utils.px(0.1), 0)
self.assertEqual(utils.px(0.6), 1)