Exemplo n.º 1
0
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,
    )
Exemplo n.º 2
0
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,
    )
Exemplo n.º 3
0
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
Exemplo n.º 4
0
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
Exemplo n.º 5
0
 def test_px(self):
     self.assertEqual(utils.px(0.1), 0)
     self.assertEqual(utils.px(0.6), 1)