def transpose(self):
""" Transpose the image (across upper-right -> lower-left axis)
:return: transposed image
:rtype: jpegtran.JPEGImage
"""
new = JPEGImage(blob=lib.Transformation(self.data).transpose())
new._update_thumbnail()
return new
def flip(self, direction):
""" Flip the image in horizontal or vertical direction.
:param direction: Flipping direction
:type direction: 'vertical' or 'horizontal'
:return: flipped image
:rtype: jpegtran.JPEGImage
"""
if direction not in ('horizontal', 'vertical'):
raise ValueError("Direction must be either 'vertical' or "
"'horizontal'")
new = JPEGImage(blob=lib.Transformation(self.data).flip(direction))
new._update_thumbnail()
return new
def rotate(self, angle):
""" Rotate the image.
:param angle: rotation angle
:type angle: -90, 90, 180 or 270
:return: rotated image
:rtype: jpegtran.JPEGImage
"""
if angle not in (-90, 90, 180, 270):
raise ValueError("Angle must be -90, 90, 180 or 270.")
img = JPEGImage(blob=lib.Transformation(self.data).rotate(angle))
# Set EXIF orientation to 'Normal' (== no rotation)
if img.exif_orientation not in (None, 1):
img.exif_orientation = 1
img._update_thumbnail()
return img
def downscale(self, width, height, quality=75):
""" Downscale the image.
:param width: Scaled image width
:type width: int
:param height: Scaled image height
:type height: int
:param quality: JPEG quality of scaled image (default: 75)
:type quality: int
:return: downscaled image
:rtype: jpegtran.JPEGImage
"""
if width == self.width and height == self.height:
return self
if width > self.width or height > self.height:
raise ValueError("jpegtran can only downscale JPEGs")
new = JPEGImage(blob=lib.Transformation(self.data)
.scale(width, height, quality))
new._update_thumbnail()
return new
def crop(self, x, y, width, height):
""" Crop a rectangular area from the image.
:param x: horizontal coordinate of upper-left corner
:type x: int
:param y: vertical coordinate of upper-left corner
:type y: int
:param width: width of area
:type width: int
:param height: height of area
:type height: int
:return: cropped image
:rtype: jpegtran.JPEGImage
"""
valid_crop = (x < self.width and y < self.height and
x+width <= self.width and y+height <= self.height)
if not valid_crop:
raise ValueError("Crop parameters point outside of the image")
new = JPEGImage(blob=lib.Transformation(self.data)
.crop(x, y, width, height))
new._update_thumbnail()
return new
def height(self):
""" Height of the image in pixels. """
return lib.Transformation(self.data).get_dimensions()[1]
def width(self):
""" Width of the image in pixels. """
return lib.Transformation(self.data).get_dimensions()[0]