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@omz omz/core_image.py
Last active Feb 27, 2018

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core_image.py
'''
This module provides a Python wrapper around CIImage and CIFilter for using CoreImage filters from Pythonista more easily.
How to use:
1) Create a CImage object. The constructor accepts either a file path, a ui.Image, PIL.Image.Image, or photos.Asset object. Example:
>>> # From a photo:
>>> img = CImage(photos.pick_asset())
>>> # From a ui.Image:
>>> img2 = CImage(ui.Image.named('test:Peppers'))
>>> # From a file:
>>> img3 = CImage('MyImage.jpg')
2) Apply a filter using the CImage object's filter() method. The list of available filters and their parameter names can be found here:
https://developer.apple.com/library/content/documentation/GraphicsImaging/Reference/CoreImageFilterReference/index.html
The result is another CImage object that can be filtered again, to build a filter chain. When all filters have been applied, you can
use the show() method to display the result in the console, or save_jpeg()/save_png() to save it to a file.
Filter parameters are passed to the filter() method as keyword arguments. If a parameter name begins with "input" (almost all do),
that prefix can be left out for better readability (e.g. inputSaturation=... becomes just saturation=...).
The filter reference will tell you which type each parameter should be. This can be translated to Python as follows:
NSNumber: int or float
CIVector: tuple of numbers (int or float), often x/y coordinates
CIImage: CImage object
CIColor: Either a color string (e.g. '#ff000', 'red'), a tuple with 3 or 4 numbers (rgb[a]) in the range 0.0-1.0,
or a number (grayscale value)
NSString: str
NSData: bytes or str (the latter will be utf-8-encoded)
Example:
>>> img = CImage(photos.pick_asset())
>>> img2 = img.filter('CIColorControls', saturation=2.0, contrast=1.5)
>>> img3 = img2.filter('CIGaussianBlur', radius=10)
>>> img3.show()
The inputImage parameter is always set automatically. If a filter doesn't have an inputImage parameter
(e.g. a gradient or barcode generator), you can just create an empty CImage and "filter" that.
Example:
>>> empty = CImage()
>>> qrcode = empty.filter('CIQRCodeGenerator', message='Hello World')
>>> qrcode.show()
'''
from objc_util import *
import photos
import os
import ui
import PIL.Image
import tempfile
import numbers
class CImage(object):
def __init__(self, img_or_path=None):
CIImage = ObjCClass('CIImage')
if img_or_path is None:
self.ci_img = CIImage.emptyImage()
return
if isinstance(img_or_path, ObjCInstance):
if img_or_path.isKindOfClass_(CIImage):
self.ci_img = img_or_path
return
if isinstance(img_or_path, PIL.Image.Image):
buffer = io.BytesIO()
img_or_path.save(buffer, 'PNG')
img_or_path = ui.Image.from_data(buffer)
if isinstance(img_or_path, photos.Asset):
img_or_path = img_or_path.get_ui_image()
if isinstance(img_or_path, ui.Image):
self.ci_img = CIImage.imageWithCGImage_(ObjCInstance(img_or_path).CGImage())
elif isinstance(img_or_path, str):
file_url = nsurl(os.path.abspath(img_or_path))
self.ci_img = CIImage.imageWithContentsOfURL_(file_url)
else:
raise TypeError('unsupported type for initializing CImage')
def filter(self, name, **params):
CIFilter = ObjCClass('CIFilter')
CIVector = ObjCClass('CIVector')
CIColor = ObjCClass('CIColor')
filter = CIFilter.filterWithName_(name)
if not filter:
raise ValueError('Invalid filter name')
filter.setDefaults()
input_keys = [str(k) for k in filter.inputKeys()]
attrs = filter.attributes()
input_key_types = {
str(k): str(attrs[k]['CIAttributeClass'])
for k in input_keys
}
supported_types = {
'CIImage': CImage,
'CIVector': tuple,
'CIColor': (tuple, numbers.Number, str),
'NSNumber': numbers.Number,
'NSData': (bytes, str),
'NSString': str
}
if 'inputImage' in input_keys:
filter.setValue_forKey_(self.ci_img, 'inputImage')
for key, value in params.items():
if key not in input_keys:
key = 'input' + key[0].upper() + key[1:]
if key not in input_keys:
raise ValueError('"%s" is not a valid parameter for %s' % (key, name))
param_type = input_key_types[key]
if param_type not in supported_types:
raise TypeError('Parameters of type %s are not supported' % param_type)
expected_type = supported_types[param_type]
type_matches = isinstance(value, expected_type)
if not type_matches:
raise TypeError(
'Incorrect type for %s parameter (expected %s, got %s)' %
(key, expected_type, type(value))
)
if param_type == 'CIColor':
if isinstance(value, numbers.Number):
value = (value, value, value, 1.0)
elif isinstance(value, str):
value = ui.parse_color(value)
if not all(isinstance(n, numbers.Number) for n in value):
raise TypeError('All color components must be numbers')
if len(value) == 3:
ci_color = CIColor.colorWithRed_green_blue_(*value)
elif len(value) == 4:
ci_color = CIColor.colorWithRed_green_blue_alpha_(*value)
else:
raise TypeError('Color must be a tuple with 3 or 4 RGB(A) values')
filter.setValue_forKey_(ci_color, key)
elif param_type == 'CIImage':
filter.setValue_forKey_(value.ci_img, key)
elif param_type == 'CIVector':
arr = (CGFloat * len(value))(*value)
vector = CIVector.vectorWithValues_count_(arr, len(value))
filter.setValue_forKey_(vector, key)
elif param_type == 'NSData' and isinstance(value, str):
filter.setValue_forKey_(value.encode('utf-8'), key)
else:
filter.setValue_forKey_(value, key)
out_img = filter.valueForKey_('outputImage')
return CImage(out_img)
def _uiimage_rep(self):
# Internal helper method for save_jpeg and save_png
ctx = ObjCClass('CIContext').context()
extent = self.ci_img.extent()
m = ctx.outputImageMaximumSize()
if extent.size.width > m.width or extent.size.height > m.height:
# This is probably an infinite image, render *something*...
extent = CGRect(CGPoint(0, 0), CGSize(1024, 1024))
cg_img = ctx.createCGImage_fromRect_(self.ci_img, extent)
ui_img = UIImage.imageWithCGImage_(cg_img)
c.CGImageRelease.argtypes = [c_void_p]
c.CGImageRelease.restype = None
c.CGImageRelease(cg_img)
return ui_img
def save_jpeg(self, filename='output.jpg', quality=1.0):
ui_img = self._uiimage_rep()
c.UIImageJPEGRepresentation.argtypes = [c_void_p, CGFloat]
c.UIImageJPEGRepresentation.restype = c_void_p
data = ObjCInstance(c.UIImageJPEGRepresentation(ui_img.ptr, quality))
filename = os.path.abspath(filename)
return data.writeToFile_atomically_(filename, True)
def save_png(self, filename='output.png'):
ui_img = self._uiimage_rep()
c.UIImagePNGRepresentation.argtypes = [c_void_p]
c.UIImagePNGRepresentation.restype = c_void_p
data = ObjCInstance(c.UIImagePNGRepresentation(ui_img.ptr))
filename = os.path.abspath(filename)
return data.writeToFile_atomically_(filename, True)
def show(self):
temp_path = os.path.join(tempfile.gettempdir(), 'cimage_show.png')
saved = self.save_png(temp_path)
if saved:
ui.Image.named(temp_path).show()
else:
raise ValueError('Image could not be saved (may be empty)')
def main():
img = CImage(ui.Image.named('test:Mandrill'))
img = img.filter('CITwirlDistortion', center=(256, 256), radius=150)
img = img.filter('CICMYKHalftone')
img.show()
if __name__ == '__main__':
main()
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