[Image-SIG] rounded corners

[Stani]

I forgot to take of the _t function, so the first lines should be:
CROSS                   = 'Cross'
ROUNDED                 = 'Rounded'
SQUARE                  = 'Square'

Stani schreef:
> In PIL this is easy.
>
> The following code preferably uses cache (just a simple python
> dictionary) to avoid the overhead of generating the same transparency
> masks. So typical use would be:
>
> cache = {}
> for image in images:
>    thumbnail = image_round(image.thumbnail(size, filter), cache, radius)
>
> Here is the code for rounded corners:
>
> # Rounded corners
> # (c) 2008 www.stani.be
> # License: same as PIL
>
> CROSS                   = _t('Cross')
> ROUNDED                 = _t('Rounded')
> SQUARE                  = _t('Square')
>
> CORNERS                 = [ROUNDED,SQUARE,CROSS]
> CORNER_ID               = 'rounded_corner_r%d_f%d'
> CROSS_POS               = (CROSS,CROSS,CROSS,CROSS)
> ROUNDED_POS             = (ROUNDED,ROUNDED,ROUNDED,ROUNDED)
> ROUNDED_RECTANGLE_ID    = 'rounded_rectangle_r%d_f%d_s%s_p%s'
>
> def round_image(image,cache={},radius=100,fill=255,pos=ROUNDED_POS,
>        back_colour='#FFFFFF'):
>    if image.mode != 'RGBA':
>        image = image.convert('RGBA')
>    mask    = create_rounded_rectangle(image.size,cache,radius,fill,pos)
>    image.paste(Image.new('RGB',image.size,back_colour),(0,0),
>        ImageChops.invert(mask))
>    image.putalpha(mask)
>    return image
>
> def create_corner(radius=100,fill=255,factor=2):
>    corner  = Image.new('L',(factor*radius,factor*radius),0)
>    draw    = ImageDraw.Draw(corner)
>    draw.pieslice((0,0,2*factor*radius,2*factor*radius),180,270,fill=fill)
>    corner  = corner.resize((radius,radius),Image.ANTIALIAS)
>    return corner
>
> def create_rounded_rectangle(size=(600,400),cache={},radius=100,fill=255,
>        pos=ROUNDED_POS):
>    #rounded_rectangle
>    im_x, im_y  = size
>    rounded_rectangle_id    = ROUNDED_RECTANGLE_ID%(radius,fill,size,pos)
>    if cache.has_key(rounded_rectangle_id):
>        return cache[rounded_rectangle_id]
>    else:
>        #cross
>        cross_id    = ROUNDED_RECTANGLE_ID%(radius,fill,size,CROSS_POS)
>        if cache.has_key(cross_id):
>            cross   = cache[cross_id]
>        else:
>            cross   = cache[cross_id]   = Image.new('L',size,0)
>            draw    = ImageDraw.Draw(cross)
>            draw.rectangle((radius,0,im_x-radius,im_y),fill=fill)
>            draw.rectangle((0,radius,im_x,im_y-radius),fill=fill)
>        if pos==CROSS_POS:
>            return cross
>        #corner
>        corner_id   = CORNER_ID%(radius,fill)
>        if cache.has_key(corner_id):
>            corner  = cache[corner_id]
>        else:
>            corner  = cache[corner_id] = create_corner(radius,fill)
>        #rounded rectangle
>        rectangle   = Image.new('L',(radius,radius),255)
>        rounded_rectangle   = cross.copy()
>        for index, angle in enumerate(pos):
>            if angle == CROSS:
>                break
>            if angle == ROUNDED:
>                element = corner
>            else:
>                element = rectangle
>            if index%2:
>                x       = im_x-radius
>                element = element.transpose(Image.FLIP_LEFT_RIGHT)
>            else:
>                x       = 0
>            if index < 2:
>                y       = 0
>            else:
>                y       = im_y-radius
>                element = element.transpose(Image.FLIP_TOP_BOTTOM)
>            rounded_rectangle.paste(element,(x,y))
>        cache[rounded_rectangle_id] = rounded_rectangle
>        return rounded_rectangle
>
>
> Alex K schreef:
>> Hello,
>>
>> Would anyone know how to generate thumbnails with rounded corners
>> using PIL? I'm also considering imagemagick if PIL turns out not to be
>> appropriate for the task.
>>
>> Thank you so much,
>>
>> Alex
>> _______________________________________________
>> Image-SIG maillist  -  Image-SIG at python.org
>> http://mail.python.org/mailman/listinfo/image-sig
>>   
>