Python Image.sample方法代码示例

# 需要导入模块: from wand.image import Image [as 别名]
# 或者: from wand.image.Image import sample [as 别名]
def create_thumb(size, blob):
    '''Creates proportionally scaled thumbnail and save to destination. Returns thumbnaill location and source mimetype'''
    mimetype = None
    with Image(blob=blob) as source:
        image = Image(source.sequence[0]) if source.sequence else source
        
        mimetype = image.mimetype
        if mimetype == None:
            raise InvalidImageException('Invalid image mimetype!')
        
        w, h = image.size
        if w > size[0]:
            h = int(max(h * size[0] / w, 1))
            w = int(size[0])
        if h > size[1]:
            w = int(max(w * size[1] / h, 1))
            h = int(size[1])
        size = w, h

        if size == image.size:
            #image.save(filename=destination + '.' + extension)
            return image, mimetype
    
        image.sample(*size)
        #image.save(filename=destination + '.' + extension)

        return image, mimetype

# 需要导入模块: from wand.image import Image [as 别名]
# 或者: from wand.image.Image import sample [as 别名]
def process_upload(upload, collection='uploads', image_size=(1280, 720),
                   thumbnail=True):
    """Processes the uploaded images in the posts and also the users avatars.
    This should be extensible in future to support the uploading of videos,
    audio, etc...

    :param _id: The ID for the post, user or anything you want as the filename
    :type _id: str
    :param upload: The uploaded Werkzeug FileStorage object
    :type upload: ``Werkzeug.datastructures.FileStorage``
    :param collection: The GridFS collection to upload the file too.
    :type collection: str
    :param image_size: The max height and width for the upload
    :type image_size: Tuple length 2 of int
    :param thumbnail: Is the image to have it's aspect ration kept?
    :type thumbnail: bool
    """
    try:
        # StringIO to take the uploaded image to transport to GridFS
        output = io.BytesIO()

        # All images are passed through Wand and turned in to PNG files.
        # Unless the image is a GIF and its format is kept
        # Will change if they need thumbnailing or resizing.
        img = Image(file=upload)

        # If the input file if a GIF then we need to know
        gif = True if img.format == 'GIF' else False
        animated_gif = True if gif and len(img.sequence) > 1 else False

        # Check the exif data.
        # If there is an orientation then transform the image so that
        # it is always looking up.
        try:
            exif_data = {
                k[5:]: v
                for k, v in img.metadata.items()
                if k.startswith('exif:')
            }

            orientation = exif_data.get('Orientation')

            orientation = int(orientation)

            if orientation:  # pragma: no branch
                if orientation == 2:
                    img.flop()
                elif orientation == 3:
                    img.rotate(180)
                elif orientation == 4:
                    img.flip()
                elif orientation == 5:
                    img.flip()
                    img.rotate(90)
                elif orientation == 6:
                    img.rotate(90)
                elif orientation == 7:
                    img.flip()
                    img.rotate(270)
                elif orientation == 8:
                    img.rotate(270)

        except (AttributeError, TypeError, AttributeError):
            pass

        if thumbnail:
            # If the GIF was known to be animated then save the animated
            # then cycle through the frames, transforming them and save the
            # output
            if animated_gif:
                animated_image = Image()
                for frame in img.sequence:
                    frame.transform(resize='{0}x{1}>'.format(*image_size))
                    # Directly append the frame to the output image
                    animated_image.sequence.append(frame)

                animated_output = io.BytesIO()
                animated_output.format = 'GIF'
                animated_image.save(file=animated_output)
                animated_output.seek(0)

            img.transform(resize='{0}x{1}>'.format(*image_size))
        else:
            # Just sample the image to the correct size
            img.sample(*image_size)
            # Turn off animated GIF
            animated_gif = False

        img.format = 'PNG'
        uuid = get_uuid()
        filename = '{0}.{1}'.format(uuid, 'png')

        # Return the file pointer to the start
        img.save(file=output)
        output.seek(0)

        # Place file inside GridFS
        m.save_file(filename, output, base=collection)

        animated_filename = ''
#.........这里部分代码省略.........

# 需要导入模块: from wand.image import Image [as 别名]
# 或者: from wand.image.Image import sample [as 别名]
## calls liquid-rescale iteratively, only 50 pixels at a time, for a better result

fname = sys.argv[1]
out_fname = sys.argv[2]
dims = sys.argv[3]
# fname = 'small/Pelagia_noctiluca_(Sardinia).jpg'
# fname = 'small/92547.jpg'
# out_fname = 'test.png'
# dims = '1600x400'

step = 125

width_out, height_out = dims.split('x')
height_out = int(height_out)
width_out = int(width_out)

img = Image(filename=fname)
width, height = img.size
ratio = min(width_out/width, height_out/height)
img.sample(int(width * ratio), int(height * ratio))


while img.width < width_out or img.height < height_out:
    print(img.size)
    diffw = min(width_out - img.width, step)
    diffh = min(height_out - img.height, step)
    img.liquid_rescale(img.width+diffw, img.height+diffh, delta_x=6)

img.save(filename=out_fname)