def trim ( self, level = 0.0 ):
""" Returns a new copy of the image with all external edges having alpha
levels <= *level* trimmed off.
"""
if isinstance( level, float ):
level = int( 255.0 * level )
level = clamped( level, 0, 255 )
a = self.a
for x1 in xrange( 0, self.width ):
if not alltrue( a[ :, x1 ] <= level ):
break
for x2 in xrange( self.width - 1, x1 - 1, -1 ):
if not alltrue( a[ :, x2 ] <= level ):
break
x2 += 1
for y1 in xrange( 0, self.height ):
if not alltrue( a[ y1, x1: x2 ] <= level ):
break
for y2 in xrange( self.height - 1, y1 - 1, -1 ):
if not alltrue( a[ y2, x1: x2 ] <= level ):
break
return self.crop( x1, y1, x2 - x1, y2 - y1 + 1 )
def scale ( self, size, filter = 'Lanczos3' ):
""" Returns a new ImageResource object derived from this one which has
been scaled to the size specified by *size* using the image filter
specified by *filter*.
*Size* may either be a tuple of the form (width, height) specifying
the target image width and height in pixels (e.g. (100,80)), or a
single float value representing the image scaling factor (e.g. 0.5).
If the tuple form is used, one of the two values may be zero (e.g.
(100,0)). In this case, the zero value will be replaced by the
scaled width or height needed to preserve the current aspect ratio
of the image based on the other, non-zero value specified. This
could be useful when trying to create thumbnail images with a
common width (or height) for example.
*filter* specifies the optional name of the image filter to use
while scaling the image. The possible values are:
- Bell
- Box
- CatmullRom
- Cosine
- CubicConvolution
- CubicSpline
- Hermite
- Lanczos3 (default)
- Lanczos8
- Mitchell
- Quadratic
- QuadraticBSpline
- Triangle
"""
global filter_map
from facets.api import toolkit
from facets.ui.pyface.image_resource import ImageResource
if isinstance( size, tuple ):
width, height = size
if width == 0:
width = round( float( self.width * height ) / self.height )
elif height == 0:
height = round( float( self.height * width ) / self.width )
else:
width = round( self.width * size )
height = round( self.height * size )
width = clamped( int( width ), 1, 8192 )
height = clamped( int( height ), 1, 8192 )
if (width == self.width) and (height == self.height):
return self
pixels = image_transform(
self.pixels.tostring(),
self.width, self.height, width, height, filter_map[ filter ]
)
image = ImageResource(
bitmap = toolkit().create_bitmap( pixels, width, height )
)
# Save the pixel data to avoid it being garbage collected:
image._buffer = pixels
return image
