How to access VisionKit?

JonB

But the built in objc methods for writing to PDF (see link above) ought to be reasonably fast. I haven't tried.

cvp

@JonB said:

can PIL do multipage PDF? I guess you still would need to do the ui2pil type business.

I don't think it does multi pages, but easy to do it yourself via PdfFileMerger.
Yes for ui2pil

cvp

@JonB said:

But the built in objc methods for writing to PDF (see link above) ought to be reasonably fast. I haven't tried

I have already done the inverse (PDF -> image) via Objectivec context.. quick 🙄

emkay_online

@cvp Thank you so much for this code. It works a treat and really gives me a solid foundation to build on.

Also thank you for giving me a good grounding in the objc_util module - it's certainly a complex one, especially for someone with no iOS coding experience.

Thank you.

cvp

@emkay_online you should dismiss the viewcontroller in the didcancel delegate, not in the didfinish like I did for testing only. This if you want to process multiple scans

cvp

@JonB said:

But the built in objc methods for writing to PDF (see link above) ought to be reasonably fast. I haven't tried.

Please applaus. ok, I exaggerate 😂, but was not so easy (for me)

from objc_util import *
import ui

UIGraphicsGetCurrentContext = c.UIGraphicsGetCurrentContext
UIGraphicsGetCurrentContext.restype = c_void_p
UIGraphicsGetCurrentContext.argtypes = []

UIGraphicsBeginPDFContextToData = c.UIGraphicsBeginPDFContextToData
UIGraphicsBeginPDFContextToData.restype = None
UIGraphicsBeginPDFContextToData.argtypes = [c_void_p, CGRect, c_void_p]

UIGraphicsBeginPDFPage = c.UIGraphicsBeginPDFPage
UIGraphicsBeginPDFPage.restype = None
UIGraphicsBeginPDFPage.argtypes = []

UIGraphicsEndPDFContext = c.UIGraphicsEndPDFContext
UIGraphicsEndPDFContext.restype = None
UIGraphicsEndPDFContext.argtypes = []

pdfdata = NSMutableData.alloc()#.init()
ui_image = ui.Image.named('test:Lenna')
uiimage = ObjCInstance(ui_image)
w,h = ui_image.size
frame = CGRect(CGPoint(0, 0), CGSize(w, h))	
UIGraphicsBeginPDFContextToData(pdfdata, frame, None)
UIGraphicsBeginPDFPage()
pdfContext = UIGraphicsGetCurrentContext()
uiimage.drawInRect_(frame)
UIGraphicsEndPDFContext()
# just to be sure that pdfdata is ok
with open('a.pdf',mode='wb') as fil:
	b = nsdata_to_bytes(pdfdata)
	fil.write(b)

JonB

👏👏👏

If you are going straight to file, you might consider using

https://developer.apple.com/documentation/uikit/1623927-uigraphicsbeginpdfcontexttofile?language=objc

instead of creating the context as nsdata. Might save a few lines.

Also, you can use drawAtPoint instead of drawInRect, so that you don't need to specify w,h.

I think if you omit the frame when you create the context, it also create an 8.5x11.

cvp

@JonB said:

so that you don't need to specify w,h.

Yes but UIGraphicsBeginPDFContextToData needs it also

Édit: sorry, written before reading your last line

cvp

I don't say it is the best way, it was only an exercice for me.

cvp

@JonB said:

instead of creating the context as nsdata.

I added the file lines only to test /check pdfdata.