PDF rendering with PDFBox, from Python

pdfbox.py

# SPDX-FileCopyrightText: 2023 geisserml <geisserml@gmail.com>
# SPDX-License-Identifier: Apache-2.0

# Assuming you have an Apache PDFBox 3 jar in the same directory

from pathlib import Path
import jpype
import jpype.imports
import PIL.Image

RELATIVE_DIR = Path(__file__).resolve().parent
PDFBOX_JAR = RELATIVE_DIR / "pdfbox.jar"
jpype.addClassPath(PDFBOX_JAR)
jpype.startJVM("-Djava.awt.headless=true")

import java.io as jio
import org.apache.pdfbox as pdfbox
from org.apache.pdfbox.rendering import ImageType


DPI = 300
TEST_FILE = Path("~/projects/scripts/out/38.pdf").expanduser()
OUTPUT_DIR = RELATIVE_DIR / "out"
OUTPUT_DIR.mkdir(exist_ok=True)


ImageTypeToPIL = {
    ImageType.BINARY: "1",     # TYPE_BYTE_BINARY
    ImageType.GRAY:   "L",     # TYPE_BYTE_GRAY
    ImageType.RGB:    "BGRX",  # TYPE_INT_RGB, actually BGRX in memory
    ImageType.ARGB:   "BGRA",  # TYPE_INT_ARGB, actually BGRA in memory
    ImageType.BGR:    "BGR",   # TYPE_3BYTE_BGR
}


imgtype = ImageType.BGR
pil_srcmode = ImageTypeToPIL[imgtype]
pil_dstmode = pil_srcmode.replace("BGR", "RGB")

pdf = pdfbox.Loader.loadPDF( jio.File(str(TEST_FILE)) )
renderer = pdfbox.rendering.PDFRenderer(pdf)
n_pages = int( pdf.getNumberOfPages() )

for i in range(n_pages):
    
    print(f"Rendering page {i+1} ...")
    
    j_image = renderer.renderImageWithDPI(i, DPI, imgtype)
    w, h = int(j_image.getWidth()), int(j_image.getHeight())
    
    j_data = j_image.getRaster().getDataBuffer().getData()
    py_data = memoryview(j_data)  # requires PIL >= 9.5
    
    py_image = PIL.Image.frombuffer(pil_dstmode, (w, h), py_data, "raw", pil_srcmode, 0, 1)
    py_image.save(OUTPUT_DIR / f"render_{i+1}.jpg")


jpype.shutdownJVM()

todo: might theoretically want to handle offset, though it always seems to be 0 in practice, as per my testing

also want to look into different input types (bytes, byte buffer), and parallelization, as would be relevant in a generic API