readme.md

Aspose.Imaging for Python via .NET API allows to easy manipulate your djvu images or photos in your Python application or Web service.

You can:

• Convert djvu image to raster formats;
• Convert djvu image to vector formats;
• Perform crop, rotate, resize and other typical operations to djvu images;
• Process multi-page djvu images and convert to multi-page formats (i.e. pdf, tiff, gif, apng etc)

Interested ?

You may go further at : https://products.aspose.com/imaging/python-net/

convert-djvu-to-pdf.py

import aspose.pycore as aspycore
from aspose.imaging import Image, IntRange
from aspose.imaging.fileformats.djvu import DjvuImage
from aspose.imaging.fileformats.pdf import PdfDocumentInfo
from aspose.imaging.imageoptions import PdfOptions, DjvuMultiPageOptions
import os


if 'TEMPLATE_DIR' in os.environ:
	templates_folder = os.environ['TEMPLATE_DIR']
else:
	templates_folder = r"C:\Users\USER\Downloads\templates"

delete_output = 'SAVE_OUTPUT' not in os.environ
data_dir = templates_folder
# Load a DjVu image
with aspycore.as_of(Image.load(os.path.join(data_dir, "template.djvu")), DjvuImage) as image:
	# Create an instance of PdfOptions and Initialize the metadata for Pdf document
	export_options = PdfOptions()
	export_options.pdf_document_info = PdfDocumentInfo()
	# Create an instance of IntRange and initialize it with the range of DjVu pages to be exported
	range_ = IntRange(0, 1)
	# Initialize an instance of DjvuMultiPageOptions with range of DjVu pages to be exported and Save the result in PDF format
	export_options.multi_page_options = DjvuMultiPageOptions(range_)
	image.save(os.path.join(data_dir, "result.pdf"), export_options)

if delete_output:
	os.remove(os.path.join(data_dir, "result.pdf"))

convert-djvu-to-tiff.py

import aspose.pycore as aspycore
from aspose.imaging import Image
from aspose.imaging.fileformats.djvu import DjvuImage
from aspose.imaging.fileformats.tiff.enums import TiffExpectedFormat
from aspose.imaging.imageoptions import TiffOptions, DjvuMultiPageOptions
import os


if 'TEMPLATE_DIR' in os.environ:
	templates_folder = os.environ['TEMPLATE_DIR']
else:
	templates_folder = r"C:\Users\USER\Downloads\templates"

delete_output = 'SAVE_OUTPUT' not in os.environ
data_dir = templates_folder
# Load a DjVu image
with aspycore.as_of(Image.load(os.path.join(data_dir, "template.djvu")), DjvuImage) as image:
	# Create an instance of TiffOptions & use preset options for Black n While with Deflate compression
	export_options = TiffOptions(TiffExpectedFormat.TIFF_DEFLATE_BW)
	# Initialize the DjvuMultiPageOptions and Call Save method while passing instance of TiffOptions
	export_options.multi_page_options = DjvuMultiPageOptions()
	image.save(os.path.join(data_dir, "result.tiff"), export_options)

if delete_output:
	os.remove(os.path.join(data_dir, "result.tiff"))

convert-range-of-djvu-pages.py

import aspose.pycore as aspycore
from aspose.imaging import Image, IntRange
from aspose.imaging.fileformats.djvu import DjvuImage
from aspose.imaging.fileformats.tiff.enums import TiffExpectedFormat
from aspose.imaging.imageoptions import TiffOptions, DjvuMultiPageOptions
import os


if 'TEMPLATE_DIR' in os.environ:
	templates_folder = os.environ['TEMPLATE_DIR']
else:
	templates_folder = r"C:\Users\USER\Downloads\templates"

delete_output = 'SAVE_OUTPUT' not in os.environ
data_dir = templates_folder
# Load a DjVu image
with aspycore.as_of(Image.load(os.path.join(data_dir, "template.djvu")), DjvuImage) as image:
	# Create an instance of TiffOptions & use preset options for Black n While with Deflate compression
	export_options = TiffOptions(TiffExpectedFormat.TIFF_DEFLATE_BW)
	range_ = IntRange(0, 1)
	# Initialize an instance of DjvuMultiPageOptions while passing instance of IntRange and  Call Save method while passing instance of TiffOptions
	export_options.multi_page_options = DjvuMultiPageOptions(range_)
	image.save(os.path.join(data_dir, "result.tiff"), export_options)

if delete_output:
	os.remove(os.path.join(data_dir, "result.tiff"))

convert-specific-portion-of-djvu-pages.py

import aspose.pycore as aspycore
from aspose.imaging import Image, IntRange, Rectangle
from aspose.imaging.fileformats.png import PngColorType
from aspose.imaging.fileformats.djvu import DjvuImage
from aspose.imaging.imageoptions import PngOptions, DjvuMultiPageOptions
import os


if 'TEMPLATE_DIR' in os.environ:
	templates_folder = os.environ['TEMPLATE_DIR']
else:
	templates_folder = r"C:\Users\USER\Downloads\templates"

delete_output = 'SAVE_OUTPUT' not in os.environ
data_dir = templates_folder
# Load a DjVu image
with aspycore.as_of(Image.load(os.path.join(data_dir, "template.djvu")), DjvuImage) as image:
	# Create an instance of PngOptions and Set ColorType to Grayscale
	export_options = PngOptions()
	export_options.color_type = PngColorType.GRAYSCALE
	# Create an instance of Rectangle and specify the portion on DjVu page
	export_area = Rectangle(0, 0, 500, 500)
	# Specify the DjVu page index and Initialize an instance of DjvuMultiPageOptions while passing index of DjVu page index and instance of Rectangle covering the area to be exported               
	export_page_index = 0
	export_options.multi_page_options = DjvuMultiPageOptions(export_page_index, export_area)
	image.save(os.path.join(data_dir, "result.png"), export_options)

if delete_output:
	os.remove(os.path.join(data_dir, "result.png"))

memory-strategy-optimization-djvu.py

import aspose.pycore as aspycore
from aspose.imaging import Image, LoadOptions
from aspose.imaging.fileformats.djvu import DjvuImage
from aspose.imaging.imageoptions import PngOptions
import os


if 'TEMPLATE_DIR' in os.environ:
	templates_folder = os.environ['TEMPLATE_DIR']
else:
	templates_folder = r"C:\Users\USER\Downloads\templates"

delete_output = 'SAVE_OUTPUT' not in os.environ
data_dir = templates_folder
# Setting a memory limit of 50 megabytes for target loaded image
obj_init = LoadOptions()
obj_init.buffer_size_hint = 50
with aspycore.as_of(Image.load(os.path.join(data_dir, "template.djvu"), obj_init), DjvuImage) as image:
	page_num = 0
	for page in image.pages:
		out_file = os.path.join(data_dir, f"page{page_num}.png")
		page.save(out_file, PngOptions())
		if delete_output:
			os.remove(out_file)
		page_num += 1

parallel-djvu-images-processing-using-multithreading.py

import aspose.pycore as aspycore
from aspose.imaging import Image
from aspose.imaging.imageoptions import PngOptions
import os
import threading


if 'TEMPLATE_DIR' in os.environ:
	templates_folder = os.environ['TEMPLATE_DIR']
else:
	templates_folder = r"C:\Users\USER\Downloads\templates"

delete_output = 'SAVE_OUTPUT' not in os.environ
data_dir = templates_folder
num_threads = 5

def thread_func(path, output_file):
	try:
		with Image.load(path) as image:
			image.save(output_file, PngOptions())
	finally:
		if delete_output:
			os.remove(output_file)

input_file = os.path.join(data_dir, "template.djvu")
threads = []
for task_num in range(num_threads):
	output_file = os.path.join(data_dir, f"result_task{task_num}.png")
	thread = threading.Thread(target=thread_func, args=(input_file, output_file))
	threads.append(thread)
	thread.start()

for thread in threads:
	thread.join()