canvas.draw_image() function does not work

[Trüff]

Hey there,
I have a problem with the following code:

import canvas as cv

# creates canvas
w = 200
h = 500
cv.set_size(w, h)

# size of the image
img_w = 190
img_h = 490

cv.begin_updates()

# draws a white rectangle as the canvas background
cv.set_fill_color(1, 1, 1)
cv.fill_rect(0, 0, w, h)

# draws an image onto the canvas
cv.draw_image("image.png", 0, 0, img_w, img_h)

cv.end_updates()

Whenever is use the canvas.draw_image() function, my Pythonista crashes. This seems to be not because of the image that I‘m trying to draw, since I‘ve tried out other images and even an empty string as the 1. argument too. It didn‘t even give me an error, it just closed the program.

Am I just not using the function correctly or is there something else I need to add?

I would be really happy if someone could help me out.

[ccc]

https://omz-software.com/pythonista/docs/ios/canvas.html#canvas.draw_image
You need a "named image" not an image file name.
The first two functions of https://forum.omz-software.com/topic/2332/can-t-subclass-scene-rect-in-1-6-beta/3 might be useful.

[cvp]

@ccc said

You need a "named image"

What is that? For me, in Ui.Image.named(name), name is a file name

And the crash does not have any explanation in faultlog, only "abort"????

[cvp]

@Trüff perhaps a canvas bug, try this (with, of course, your own file name)

img = ui.Image.named('kitty.JPG')
clipboard.set_image(img)
#cv.draw_image("kitty.JPG", 0, 0, img_w, img_h)
cv.draw_clipboard(0, 0, img_w, img_h)

[ccc]

https://omz-software.com/pythonista/docs/ios/ui.html#ui.Image.named
--> cv.draw_image(ui.Image.named("image.png"), 0, 0, img_w, img_h)

[cvp]

@ccc that does not work, draw_image wants a string as first argument

cv.draw_image(ui.Image.named("kitty.JPG"), 0, 0, img_w, img_h)
TypeError: argument 1 must be str, not _ui.Image

[cvp]

@Trüff could you tell me if this solves your problem, thanks

img = ui.Image.named('image.png')
clipboard.set_image(img)
cv.draw_clipboard(0, 0, img_w, img_h)

[Trüff]

@cvp Hm… Well, it does draw the image onto the canvas. But the image I want to draw is transparent and apparently it just sets a white background for images that are saved into the clipboard. So when I draw the clipboard with the image inside of it, the picture is not transparent anymore.

[ccc]

Keep the alpha low on the background color like:

• https://forum.omz-software.com/topic/3926/transparent-scene-background-using-objc_utils

[Trüff]

@ccc Ok thank you. I‘m going to read the documentary on these modules first.

[cvp]

@ccc said

Keep the alpha low on the background color

If the image he wants to draw is transparent, its background color has already a low alpha.

[cvp]

@Trüff I don't know if you really need a canvas, else, please try this

import ui
v = ui.View()
v.background_color = 'yellow'
iv = ui.ImageView()
iv.background_color = 'red'
iv.image = ui.Image.named('image.png')
wi,hi = iv.image.size
iv.frame = (10,10,150,150*hi/wi)
v.add_subview(iv)
v.present('fullscreen')

[Trüff]

@cvp This also doesn‘t work with transparent pictures for me. However, I tried out your previous idea of saving the image into the clipboard and drawing the clipboard but I used the class Image from the PIL module instead of the one from Pythonista‘s ui module and that worked. Thank you!

[cvp]

@Trüff saiD

This also doesn‘t work with transparent pictures for me

Weird, for me it works, the image of my example has a transparent background, here in red

[cvp]

@Trüff said

but I used the class Image from the PIL module instead of the one from Pythonista‘s ui module and that worked

👍