Python Wand converts from PDF to JPG background is incorrect

I found a so wired thing while converting a pdf to jpeg, so i'd like to figure out that maybe this is a small bug. See the converted jpg below, you could find that, the background color are all black. The image is here: www.shdowin.com/public/02.jpg However, in the source file of pdf, you can see that the background color are normal white. The image is here: www.shdowin.com/public/normal.jpg I thought this maybe my pdf file's fault, however, when i try to use Acrobat.pdf2image in .NET environment, the converted jpg shows correctly. Here is my code: ``` from wand.image import Image from wand.color import Color import os, os.path, sys def pdf2jpg(source_file, target_file, dest_width, dest_height): RESOLUTION = 300 ret = True try: with Image(filename=source_file, resolution=(RESOLUTION,RESOLUTION)) as img: img.background_color = Color('white') img_width = img.width ratio = dest_width / img_width img.resize(dest_width, int(ratio * img.height)) img.format = 'jpeg' img.save(filename = target_file) except Exception as e: ret = False return ret if __name__ == "__main__": source_file = "./02.pdf" target_file = "./02.jpg" ret = pdf2jpg(source_file, target_file, 1895, 1080) ``` Any suggestions for the issue? I have uploaded the pdf to the url: 02.pdf You can try...