CODEWITHSUNDEEP
pythoncanvasreportlab
Frank
Frank

Reputation: 71

How to save a ReportLab Canvas as PNG image?

I'm using reportlab to draw a PDF normaly used for printing. How can i save the canvas as a PNG image instead, without using additional binary tools to convert the generated pdf?

I assume i need to convert it to a reportlab Drawing, but don't see a way to do so.

from reportlab.pdfgen import canvas
c = canvas.Canvas("form.pdf", pagesize=(100, 50))
c.drawString(20, 20, 'Example …')
c.save()  # but as image

Upvotes: 1

Views: 4880

Answers (3)

Don Kirkby
Don Kirkby

Reputation: 56660

I found the suggestion in Yan Weitao's answer very helpful. Here's the equivalent of the example in your question:

from reportlab.graphics.renderPM import drawToFile
from reportlab.graphics.shapes import Drawing, String

drawing = Drawing(width=100, height=50)
drawing.contents.append(String(20, 20, 'Example …'))
drawToFile(drawing, 'example.png')

After digging into the drawToFile() function, I think you might be able to use the reportlab.graphics.renderPM.PMCanvas class instead of the standard canvas. It has a saveToFile() method, but my first attempt just generated a blank image, so you'll have to do some experimenting.

Upvotes: 0

Eduard Ilyasov
Eduard Ilyasov

Reputation: 3308

It seems that there're no functions in reportlab package to convert Canvas object to PNG image. But you can use another packages (f.e. pdf2image) to convert Canvas to PNG image.

Installation

To use pdf2image package you should install poppler and pdf2image packages. You can find installation instructions here (section "How to install")

After installation you can solve your problem using this approach:

from reportlab.pdfgen import canvas
from pdf2image import convert_from_bytes

c = canvas.Canvas("form.pdf", pagesize=(100, 50))
c.drawString(20, 20, 'Example …')
image = convert_from_bytes(c.getpdfdata())[0]
image.save('form.png')

Upvotes: 0

Yan Weitao
Yan Weitao

Reputation: 11

From the 'reportlab-userguide', I found a piece of code, not sure it is useful?

from reportlab.graphics import renderPM
d = Drawing(400, 200)
d.add(Rect(50, 50, 300, 100, fillColor=colors.yellow))
d.add(String(150, 100, 'Hello World', fontSize=18, fillColor=colors.red))
d.add(String(180, 86, 'Special characters \
\xc2\xa2\xc2\xa9\xc2\xae\xc2\xa3\xce\xb1\xce\xb2',
             fillColor=colors.red))
renderPM.drawToFile(d, 'example1.png', 'PNG')

Upvotes: 1

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