Added imagepipe example.

5 files changed, 295 insertions, 0 deletions

diff --git a/examples/imagepipe/README b/examples/imagepipe/README
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+$ imagepipe_
+
+  imagepipe is an example application that implements some
+  multi commands that chain image processing instructions
+  together.
+
+  This requires pillow.
+
+Usage:
+
+  $ pip install --editable .
+  $ imagepipe open -i example01.jpg resize -w 128 display
+  $ imagepipe open -i example02.jpg blur save
diff --git a/examples/imagepipe/example01.jpg b/examples/imagepipe/example01.jpg
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+++ b/examples/imagepipe/example01.jpg
diff --git a/examples/imagepipe/example02.jpg b/examples/imagepipe/example02.jpg
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index 0000000..b1f802e
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+++ b/examples/imagepipe/example02.jpg
diff --git a/examples/imagepipe/imagepipe.py b/examples/imagepipe/imagepipe.py
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+++ b/examples/imagepipe/imagepipe.py
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+import click
+from functools import update_wrapper
+from PIL import Image, ImageFilter, ImageEnhance
+
+
+@click.group(chain=True)
+def cli():
+    """This script processes a bunch of images through pillow in a unix
+    pipe.  One commands feeds into the next.
+
+    Example:
+
+    \b
+        imagepipe open -i example01.jpg resize -w 128 display
+        imagepipe open -i example02.jpg blur save
+    """
+
+
+@cli.resultcallback()
+def process_commands(processors):
+    """This result callback is invoked with an iterable of all the chained
+    subcommands.  As in this example each subcommand returns a function
+    we can chain them together to feed one into the other, similar to how
+    a pipe on unix works.
+    """
+    # Start with an empty iterable.
+    stream = ()
+
+    # Pipe it through all stream processors.
+    for processor in processors:
+        stream = processor(stream)
+
+    # Evaluate the stream and throw away the items.
+    for _ in stream:
+        pass
+
+
+def processor(f):
+    """Helper decorator to rewrite a function so that it returns another
+    function from it.
+    """
+    def new_func(*args, **kwargs):
+        def processor(stream):
+            return f(stream, *args, **kwargs)
+        return processor
+    return update_wrapper(new_func, f)
+
+
+def generator(f):
+    """Similar to the :func:`processor` but passes through old values
+    unchanged and does not pass through the values as parameter.
+    """
+    @processor
+    def new_func(stream, *args, **kwargs):
+        for item in stream:
+            yield item
+        for item in f(*args, **kwargs):
+            yield item
+    return update_wrapper(new_func, f)
+
+
+def copy_filename(new, old):
+    new.filename = old.filename
+    return new
+
+
+@cli.command('open')
+@click.option('-i', '--image', 'images', type=click.Path(),
+              multiple=True, help='The image file to open.')
+@generator
+def open_cmd(images):
+    """Loads one or multiple images for processing.  The input parameter
+    can be specified multiple times to load more than one image.
+    """
+    for image in images:
+        try:
+            click.echo('Opening "%s"' % image)
+            if image == '-':
+                img = Image.open(click.get_binary_stdin())
+                img.filename = '-'
+            else:
+                img = Image.open(image)
+            yield img
+        except Exception as e:
+            click.echo('Could not open image "%s": %s' % (image, e), err=True)
+
+
+@cli.command('save')
+@click.option('--filename', default='processed-%04d.png', type=click.Path(),
+              help='The format for the filename.',
+              show_default=True)
+@processor
+def save_cmd(images, filename):
+    """Saves all processed images to a series of files."""
+    for idx, image in enumerate(images):
+        try:
+            fn = filename % (idx + 1)
+            click.echo('Saving "%s" as "%s"' % (image.filename, fn))
+            yield image.save(fn)
+        except Exception as e:
+            click.echo('Could not save image "%s": %s' %
+                       (image.filename, e), err=True)
+
+
+@cli.command('display')
+@processor
+def display_cmd(images):
+    """Opens all images in an image viewer."""
+    for image in images:
+        click.echo('Displaying "%s"' % image.filename)
+        image.show()
+        yield image
+
+
+@cli.command('resize')
+@click.option('-w', '--width', type=int, help='The new width of the image.')
+@click.option('-h', '--height', type=int, help='The new height of the image.')
+@processor
+def resize_cmd(images, width, height):
+    """Resizes an image by fitting it into the box without changing
+    the aspect ratio.
+    """
+    for image in images:
+        w, h = (width or image.size[0], height or image.size[1])
+        click.echo('Resizing "%s" to %dx%d' % (image.filename, w, h))
+        image.thumbnail((w, h))
+        yield image
+
+
+@cli.command('crop')
+@click.option('-b', '--border', type=int, help='Crop the image from all '
+              'sides by this amount.')
+@processor
+def crop_cmd(images, border):
+    """Crops an image from all edges."""
+    for image in images:
+        box = [0, 0, image.size[0], image.size[1]]
+
+        if border is not None:
+            for idx, val in enumerate(box):
+                box[idx] = max(0, val - border)
+            click.echo('Cropping "%s" by %dpx' % (image.filename, border))
+            yield copy_filename(image.crop(box), image)
+        else:
+            yield image
+
+
+def convert_rotation(ctx, param, value):
+    if value is None:
+        return
+    value = value.lower()
+    if value in ('90', 'r', 'right'):
+        return (Image.ROTATE_90, 90)
+    if value in ('180', '-180'):
+        return (Image.ROTATE_180, 180)
+    if value in ('-90', '270', 'l', 'left'):
+        return (Image.ROTATE_270, 270)
+    raise click.BadParameter('invalid rotation "%s"' % value)
+
+
+def convert_flip(ctx, param, value):
+    if value is None:
+        return
+    value = value.lower()
+    if value in ('lr', 'leftright'):
+        return (Image.FLIP_LEFT_RIGHT, 'left to right')
+    if value in ('tb', 'topbottom', 'upsidedown', 'ud'):
+        return (Image.FLIP_LEFT_RIGHT, 'top to bottom')
+    raise click.BadParameter('invalid flip "%s"' % value)
+
+
+@cli.command('transpose')
+@click.option('-r', '--rotate', callback=convert_rotation,
+              help='Rotates the image (in degrees)')
+@click.option('-f', '--flip', callback=convert_flip,
+              help='Flips the image  [LR / TB]')
+@processor
+def transpose_cmd(images, rotate, flip):
+    """Transposes an image by either rotating or flipping it."""
+    for image in images:
+        if rotate is not None:
+            mode, degrees = rotate
+            click.echo('Rotate "%s" by %ddeg' % (image.filename, degrees))
+            image = copy_filename(image.transpose(mode), image)
+        if flip is not None:
+            mode, direction = flip
+            click.echo('Flip "%s" %s' % (image.filename, direction))
+            image = copy_filename(image.transpose(mode), image)
+        yield image
+
+
+@cli.command('blur')
+@click.option('-r', '--radius', default=2, show_default=True,
+              help='The blur radius.')
+@processor
+def blur_cmd(images, radius):
+    """Applies gaussian blur."""
+    blur = ImageFilter.GaussianBlur(radius)
+    for image in images:
+        click.echo('Blurring "%s" by %dpx' % (image.filename, radius))
+        yield copy_filename(image.filter(blur), image)
+
+
+@cli.command('smoothen')
+@click.option('-i', '--iterations', default=1, show_default=True,
+              help='How many iterations of the smoothen filter to run.')
+@processor
+def smoothen_cmd(images, iterations):
+    """Applies a smoothening filter."""
+    for image in images:
+        click.echo('Smoothening "%s" %d time%s' %
+                   (image.filename, iterations, iterations != 1 and 's' or '',))
+        for x in xrange(iterations):
+            image = copy_filename(image.filter(ImageFilter.BLUR), image)
+        yield image
+
+
+@cli.command('emboss')
+@processor
+def emboss_cmd(images):
+    """Embosses an image."""
+    for image in images:
+        click.echo('Embossing "%s"' % image.filename)
+        yield copy_filename(image.filter(ImageFilter.EMBOSS), image)
+
+
+@cli.command('sharpen')
+@click.option('-f', '--factor', default=2.0,
+              help='Sharpens the image.', show_default=True)
+@processor
+def sharpen_cmd(images, factor):
+    """Sharpens an image."""
+    for image in images:
+        click.echo('Sharpen "%s" by %f' % (image.filename, factor))
+        enhancer = ImageEnhance.Sharpness(image)
+        yield copy_filename(enhancer.enhance(max(1.0, factor)), image)
+
+
+@cli.command('paste')
+@click.option('-l', '--left', default=0, help='Offset from left.')
+@click.option('-r', '--right', default=0, help='Offset from right.')
+@processor
+def paste_cmd(images, left, right):
+    """Pastes the second image on the first image and leaves the rest
+    unchanged.
+    """
+    imageiter = iter(images)
+    image = next(imageiter, None)
+    to_paste = next(imageiter, None)
+
+    if to_paste is None:
+        if image is not None:
+            yield image
+        return
+
+    click.echo('Paste "%s" on "%s"' %
+               (to_paste.filename, image.filename))
+    mask = None
+    if to_paste.mode == 'RGBA' or 'transparency' in to_paste.info:
+        mask = to_paste
+    image.paste(to_paste, (left, right), mask)
+    image.filename += '+' + to_paste.filename
+    yield image
+
+    for image in imageiter:
+        yield image
diff --git a/examples/imagepipe/setup.py b/examples/imagepipe/setup.py
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+++ b/examples/imagepipe/setup.py
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+from setuptools import setup
+
+setup(
+    name='click-example-imagepipe',
+    version='1.0',
+    py_modules=['imagepipe'],
+    include_package_data=True,
+    install_requires=[
+        'Click',
+        'pillow',
+    ],
+    entry_points='''
+        [console_scripts]
+        imagepipe=imagepipe:cli
+    ''',
+)