Using Pillow and img2pdf to convert images to pdf

Question

I have a task that requires me to get data from an image upload (jpg or png), resize it based on the requirement, and then transform it into pdf and then store in s3.

1. The file comes in as ByteIO
2. I have Pillow available so I can resize the image with it
3. Now the file type is class 'PIL.Image.Image' and I don't know how to proceed.
4. I found img2pdf library on https://gitlab.mister-muffin.de/josch/img2pdf, but I don't know how to use it when I have PIL format (use tobytes()?)
5. The s3 upload also looks like a file-like object, so I don't want to save it into a temp file before loading it again. Do I even need img2pdf in this case then?

How do I achieve this goal?

EDIT: I tried using tobytes() and upload to s3 directly. Upload was successful. However, when downloading to see the content, it shows an empty page. It seems like the file data is not written into the pdf file

EDIT 2: Actually went on the s3 and check the file stored. When I download it and open it, it shows cannot be opened

EDIT 3: I don't really have working code as I'm still experimenting what could work, but here's a gist

data = request.FILES['file'].file  # where the data is
im = Image.open(data)
(width, height) = (im.width // 2, im.height // 2)  # example action I wanna take with Pillow
data = im_resized.tobytes()
# potential step for using img2pdf here but I don't know how
# img2pdf.convert(data)  # this fails because "ImageOpenError: cannot read input image (not jpeg2000). PIL: error reading image: cannot identify image file <_io.BytesIO..."
# img2pdf.convert(im_resized)  # this also fails because "TypeError: Neither implements read() nor is str or bytes"
upload_to_s3(data)  # some function that utilizes boto3 to upload to s3

Answer 1

The problem is that u use Image.Image object instead of JPEG or something like it

Try this:

bytes_io = io.BytesIO()

image.save(bytes_io, 'PNG')

with open(output_pdf, "wb") as f:
    f.write(img2pdf.convert(bytes_io.getvalue()))