How to use ghostscript - 7 common examples

# Read headphone model from the PDF
        f = open(input_file, 'rb')
        text = PyPDF2.PdfFileReader(f).getPage(0).extractText()
        if 'crinacle' in text.lower():
            raise ValueError('Measured by Crinacle')

        # Convert to image with ghostscript
        # Using temporary paths with Ghostscript because it seems to be unable to work with non-ascii characters
        tmp_in = os.path.join(os.path.split(input_file)[0], '__tmp.pdf')
        tmp_out = os.path.join(os.path.split(output_file)[0], '__tmp.png')
        if tmp_in == input_file or tmp_out == output_file:
            # Skip tmp files in case it was passed as input
            raise ValueError('tmp file')
        shutil.copy(input_file, tmp_in)
        gs = Ghostscript(
            b'pdf2png',
            b'-dNOPAUSE',
            b'-sDEVICE=png16m',
            b'-dBATCH',
            b'-r600',
            b'-dUseCropBox',
            f'-sOutputFile={tmp_out}'.encode('utf-8'),
            tmp_in.encode('utf-8')
        )
        gs.exit()
        shutil.copy(tmp_out, output_file)
        print('\nSaved image to "{}"\n'.format(output_file))
        f.close()

        return Image.open(output_file)

def pdf_to_image(input_file, output_file):
    input_file = os.path.abspath(input_file)
    output_file = os.path.abspath(output_file)

    # Read headphone model from the PDF
    f = open(input_file, 'rb')

    # Convert to image with ghostscript
    # Using temporary paths with Ghostscript because it seems to be unable to work with non-ascii characters
    tmp_in = os.path.join(os.path.split(input_file)[0], '__tmp.pdf')
    tmp_out = os.path.join(os.path.split(output_file)[0], '__tmp.png')
    if tmp_in == input_file or tmp_out == output_file:
        return
    shutil.copy(input_file, tmp_in)
    Ghostscript(
        b'pdf2png',
        b'-dNOPAUSE',
        b'-sDEVICE=png16m',
        b'-dBATCH',
        b'-r600',
        b'-dUseCropBox',
        f'-sOutputFile={tmp_out}'.encode('utf-8'),
        tmp_in.encode('utf-8')
    )
    shutil.copy(tmp_out, output_file)
    print('\nSaved image to "{}"\n'.format(output_file))
    f.close()

    return Image.open(output_file)

else:
            log.crit("Input file is neither pdf nor postscript.")
            sys.exit(1)

        # Convert postscript to eps.
        log.info('Converting input postscript to EPS.')
        eps = ps_to_eps(job.file, self.width, self.height)

        if self.debug:
            # Debug enabled so writing the generated eps file.
            out_file = "%s.eps" % self.debug_basename(job)
            self.debug_write(out_filename, eps)

        # run ghostscript on eps
        log.info('Running ghostscript on eps file.')
        (raster, vector) = ghostscript.execute(
            eps, self.resolution,
            self.width, self.height,
            ghostscript.raster_mode_to_ghostscript(self.raster_mode))

        # convert image data to pcl
        log.info('Converting image data to PCL.')
        pcl = self.raster_to_pcl(raster)

        # convert vector data to hpgl
        log.info('Converting ghostscript vector data to HPGL')
        hpgl = self.vector_to_hpgl(vector)

        # send to printer
        log.info('Sending data to printer.')
        self.send(self.hpgl_pcl_to_pjl(job, hpgl, pcl))

stored = True
	process_time = None
	f = request['file']
	filename = f.name
	destination = open('%s/%s' % (settings.MEDIA_ROOT + '/uploads/', filename), 'wb')
	for chunk in f.chunks():
		destination.write(chunk)
	destination.close()
    
	file = settings.MEDIA_ROOT + '/uploads/' + filename
	hash = get_hash_data(file, "md5") #grab the hash so we can see if the file is present

	image_path = settings.MEDIA_ROOT + '/previews/' + hash + ".png"
	args = ["-dSAFER","-dBATCH","-dNOPAUSE","-sDEVICE=png16m","-r300","-dFirstPage=1","-dLastPage=1","-sOutputFile=" + image_path,file]
	try:
		ghostscript.Ghostscript(*args)
		image_generation = True
	except:
		image_generation = False
	
	is_present = get_sample(hash) #grabs the sample if it is there, if not then it runs
	if is_present == None:
		user = None
		t = time()
		output = build_obj(file) #build the raw object
		process_time = time() - t
		data = jPdf(json.loads(output)) #build the class object
		store_it = store_sample(output) #try and store the raw data
		if store_it == None:
			error_text = hash + '_store_error'
			rsesh[error_text] = True #we can let the user know if it stored with this (true an error happened)
			stored = False

f = open(input_file, 'rb')
    pdf = PyPDF2.PdfFileReader(f)
    page = pdf.getPage(0)
    try:
        t = page.extractText()
        start_ind = t.index('All rights reserved.') + len('All rights reserved.')
        end_ind = t.index('%THD+noise')
        name = t[start_ind:end_ind]
        print('Read "{name}" in "{fp}"'.format(name=name, fp=input_file))
    except:
        print('Fail to read "{}"'.format(input_file))
        return

    # Convert to image with ghostscript
    output_file_path = '{}.png'.format(os.path.join(output_dir, name))
    Ghostscript(
        b'pdf2png',
        b'-dNOPAUSE',
        b'-sDEVICE=png16m',
        b'-dBATCH',
        b'-r600',
        b'-dUseCropBox',
        '-sOutputFile={}'.format(output_file_path).encode('utf-8'),
        input_file.encode('utf-8')
    )
    print('\nSaved image to "{}"\n'.format(output_file_path))
    f.close()

tmp_pdf.write(document.get_file_obj().read())
        tmp_pdf.close()
        args = [
            'gs',
            '-q',  # Quiet
            '-dSAFER',
            '-sDEVICE=png16m',  # Type. PNG used
            '-r10',  # resolution of the thumbnail
            '-dBATCH',  # Quit GS after converting
            '-dNOPAUSE',  # Do not stop on pages
            '-dFirstPage=1',
            '-dLastPage=1',
            '-sOutputFile=%s.png' % thumbnail_temporary,  # Destination
            '%s' % thumbnail_temporary,  # Source
        ]
        ghostscript.Ghostscript(*args)
        # Deleting the temp PDF
        os.unlink(thumbnail_temporary)

# Convert postscript to eps.
        log.info('Converting input postscript to EPS.')
        eps = ps_to_eps(job.file, self.width, self.height)

        if self.debug:
            # Debug enabled so writing the generated eps file.
            out_file = "%s.eps" % self.debug_basename(job)
            self.debug_write(out_filename, eps)

        # run ghostscript on eps
        log.info('Running ghostscript on eps file.')
        (raster, vector) = ghostscript.execute(
            eps, self.resolution,
            self.width, self.height,
            ghostscript.raster_mode_to_ghostscript(self.raster_mode))

        # convert image data to pcl
        log.info('Converting image data to PCL.')
        pcl = self.raster_to_pcl(raster)

        # convert vector data to hpgl
        log.info('Converting ghostscript vector data to HPGL')
        hpgl = self.vector_to_hpgl(vector)

        # send to printer
        log.info('Sending data to printer.')
        self.send(self.hpgl_pcl_to_pjl(job, hpgl, pcl))

        # Successfully completed printing job.
        log.info("Job %s printed." % job)