Cyanic SD - ControlNet preview - Division by zero error

[Miraihi]

Each time I click "Preview" after choosing the ColtrolNet model and preprocessor, I get the following error. No preview appears. ControlNet still works though.

Exception
Python 3.10.7: C:\Program Files (x86)\Steam\steamapps\common\Krita\krita\bin\krita.exe
Thu Oct 19 19:57:18 2023

A problem occurred in a Python script.  Here is the sequence of
function calls leading up to the error, in the order they occurred.

 C:\Users\Miraihi\AppData\Roaming\krita\pykrita\cyanic\extension_widgets\controlnet.py in <lambda>()
  176         # Preview Preprocessor button
  177         self.preview_preprocessor_btn = QPushButton("Preview")
  178         self.preview_preprocessor_btn.clicked.connect(lambda: self.gen_preview())
  179         self.layout().addWidget(self.preview_preprocessor_btn)
  180 
self = <cyanic.extension_widgets.controlnet.ControlNetUnit object>
self.preview_preprocessor_btn = <PyQt5.QtWidgets.QPushButton object>
self.preview_preprocessor_btn.clicked = <bound PYQT_SIGNAL clicked of QPushButton object>
self.preview_preprocessor_btn.clicked.connect = <built-in method connect of PyQt5.QtCore.pyqtBoundSignal object>
self.gen_preview = <bound method ControlNetUnit.gen_preview of <cya...ension_widgets.controlnet.ControlNetUnit object>>

 C:\Users\Miraihi\AppData\Roaming\krita\pykrita\cyanic\extension_widgets\controlnet.py in gen_preview(self=<cyanic.extension_widgets.controlnet.ControlNetUnit object>)
  432         results = self.cnapi.preview(image_data['input_image'], self.preprocessor, self.variables['preprocessor_resolution'], self.variables['threshold_a'], self.variables['threshold_b'])
  433         kc = KritaController()
  434         kc.results_to_layers(results, self.img_in.size_dict['x'], self.img_in.size_dict['y'], self.img_in.size_dict['w'], self.img_in.size_dict['h'], 'ControlNet Preview')
  435         # NOTE: For OpenPose, results includes {'poses': [{'people': [{'pose_keypoints_2d': [...]}] }]}
  436         # Those pose_keypoints_2d could be used to make a Vector preview of the pose, allowing users to edit the pose more precisely
kc = <cyanic.krita_controller.KritaController object>
kc.results_to_layers = <bound method KritaController.results_to_layers of <cyanic.krita_controller.KritaController object>>
results = {'images': ['iVBORw0KGgoAAAANSUhEUgAAAgAAAAMPCAAAAACGMjJHAAAa...NQMeYQgA4fztmEABvBm7If0LVW4m/+aLcAAAAAElFTkSuQmCC'], 'info': 'Success'}
self = <cyanic.extension_widgets.controlnet.ControlNetUnit object>
self.img_in = <cyanic.widgets.image_in.ImageInWidget object>
self.img_in.size_dict = {'h': 987, 'w': 645, 'x': 303, 'y': 813}

 C:\Users\Miraihi\AppData\Roaming\krita\pykrita\cyanic\krita_controller.py in results_to_layers(self=<cyanic.krita_controller.KritaController object>, results={'images': ['iVBORw0KGgoAAAANSUhEUgAAAgAAAAMPCAAAAACGMjJHAAAa...NQMeYQgA4fztmEABvBm7If0LVW4m/+aLcAAAAAElFTkSuQmCC'], 'info': 'Success'}, x=303, y=813, w=645, h=987, layer_name='ControlNet Preview')
  174                 img_layer_parent.addChildNode(layer, None)
  175                 if img_w != w or img_h != h:
  176                     self.transform_to_width_height(layer, x, y, w, h)
  177                 self.doc.refreshProjection()
  178 
self = <cyanic.krita_controller.KritaController object>
self.transform_to_width_height = <bound method KritaController.transform_to_width...<cyanic.krita_controller.KritaController object>>
layer = <PyKrita.krita.Node object>
x = 303
y = 813
w = 645
h = 987

 C:\Users\Miraihi\AppData\Roaming\krita\pykrita\cyanic\krita_controller.py in transform_to_width_height(self=<cyanic.krita_controller.KritaController object>, layer=<PyKrita.krita.Node object>, x=303, y=813, width=645, height=987)
  304                 self.scale_layer(layer, x, y, width, height)
  305         except Exception as e:
  306             raise Exception('Cyanic SD - %s' % e)
  307             self.scale_layer(layer, x, y, width, height)
  308 
builtinException = <class 'Exception'>
e undefined
Exception: Cyanic SD - division by zero
    __cause__ = None
    __class__ = <class 'Exception'>
    __context__ = ZeroDivisionError('division by zero')
    __delattr__ = <method-wrapper '__delattr__' of Exception object>
    __dict__ = {}
    __dir__ = <built-in method __dir__ of Exception object>
    __doc__ = 'Common base class for all non-exit exceptions.'
    __eq__ = <method-wrapper '__eq__' of Exception object>
    __format__ = <built-in method __format__ of Exception object>
    __ge__ = <method-wrapper '__ge__' of Exception object>
    __getattribute__ = <method-wrapper '__getattribute__' of Exception object>
    __gt__ = <method-wrapper '__gt__' of Exception object>
    __hash__ = <method-wrapper '__hash__' of Exception object>
    __init__ = <method-wrapper '__init__' of Exception object>
    __init_subclass__ = <built-in method __init_subclass__ of type object>
    __le__ = <method-wrapper '__le__' of Exception object>
    __lt__ = <method-wrapper '__lt__' of Exception object>
    __ne__ = <method-wrapper '__ne__' of Exception object>
    __new__ = <built-in method __new__ of type object>
    __reduce__ = <built-in method __reduce__ of Exception object>
    __reduce_ex__ = <built-in method __reduce_ex__ of Exception object>
    __repr__ = <method-wrapper '__repr__' of Exception object>
    __setattr__ = <method-wrapper '__setattr__' of Exception object>
    __setstate__ = <built-in method __setstate__ of Exception object>
    __sizeof__ = <built-in method __sizeof__ of Exception object>
    __str__ = <method-wrapper '__str__' of Exception object>
    __subclasshook__ = <built-in method __subclasshook__ of type object>
    __suppress_context__ = False
    __traceback__ = <traceback object>
    args = ('Cyanic SD - division by zero',)
    with_traceback = <built-in method with_traceback of Exception object>

The above is a description of an error in a Python program.  Here is
the original traceback:

Traceback (most recent call last):
  File "C:\Users\Miraihi\AppData\Roaming\krita\pykrita\cyanic\krita_controller.py", line 302, in transform_to_width_height
    self.use_transform_mask(layer, x, y, width, height)
  File "C:\Users\Miraihi\AppData\Roaming\krita\pykrita\cyanic\krita_controller.py", line 322, in use_transform_mask
    scale_x = width / bounds.width() * 1.0 # 0.4
ZeroDivisionError: division by zero

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "C:\Users\Miraihi\AppData\Roaming\krita\pykrita\cyanic\extension_widgets\controlnet.py", line 178, in <lambda>
    self.preview_preprocessor_btn.clicked.connect(lambda: self.gen_preview())
  File "C:\Users\Miraihi\AppData\Roaming\krita\pykrita\cyanic\extension_widgets\controlnet.py", line 434, in gen_preview
    kc.results_to_layers(results, self.img_in.size_dict['x'], self.img_in.size_dict['y'], self.img_in.size_dict['w'], self.img_in.size_dict['h'], 'ControlNet Preview')
  File "C:\Users\Miraihi\AppData\Roaming\krita\pykrita\cyanic\krita_controller.py", line 176, in results_to_layers
    self.transform_to_width_height(layer, x, y, w, h)
  File "C:\Users\Miraihi\AppData\Roaming\krita\pykrita\cyanic\krita_controller.py", line 306, in transform_to_width_height
    raise Exception('Cyanic SD - %s' % e)
Exception: Cyanic SD - division by zero

[Miraihi]

EDIT: It actually doesn't happen with all preprocessors. But it does with Canny and Lineart at least.

[DrCyanide]

What preprocessor are you trying it out with? I'm pretty sure not all preprocessors have preview options, which could be contributing to the bug (even if I should still be handling it more gracefully than that)

[Miraihi]

Every Lineart preprocessor bugs like that. Also the stock Canny preprocessor. Openpose works fine.

[DrCyanide]

I think this is fixed now, with proper support for the grayscale preview images, but please double check and re-open this if it's not.

I was getting different errors (not Divide by Zero) when I was testing it, but I think I that's because this was reported before ControlNet defaulted to using the canvas if no image was selected, so an empty image would have a height and width of zero.