How to binarize an image

How to binarize an image

         To transform an image to a black-and-white binary form you can use the binarization method with fixed threshold BinarizeFixed, so, in this case, you need to indicate a threshold in a range of 0 and 255. All pixels of the image that have an intensity greater than the selected threshold will be assigned to value 255 (black color), or 0 (white color) otherwise. The more precise method is a `Bradly` method BinarizeBradley is used to improve binarization quality. The method calculates the threshold adaptively based on the average intensity estimation of the surrounding area with size `s x s`. The resulting picture will have more smooth edges in this case. Also, you can use Otsu method (`BinarizeOtsu`) with an automatic threshold.

from aspose.imaging import *
from aspose.imaging.fileformats.bmp import *
from aspose.imaging.fileformats.dicom import *
from aspose.imaging.fileformats.emf import *
from aspose.imaging.fileformats.jpeg import *
from aspose.imaging.fileformats.jpeg2000 import *
from aspose.imaging.fileformats.png import *
from aspose.imaging.fileformats.psd import *
from aspose.imaging.fileformats.tiff.enums import *
from aspose.imaging.imagefilters.filteroptions import *
from aspose.imaging.imageoptions import *
from aspose.imaging.masking import *
from aspose.imaging.masking.options import *
from aspose.imaging.masking.result import *
from aspose.imaging.sources import *
from aspose.pycore import as_of, is_assignable
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


def binarize_otsu():
	filter_images(lambda image: image.binarize_otsu(), "binarizeotsu")


def binarize_bradley():
	filter_images(lambda image: image.binarize_bradley(0.5), "binarizebradley")


def binarize_fixed():
	filter_images(lambda image: image.binarize_fixed(70), "binarizefixed")
	

def filter_images(do_filter, filter_name):
	obj_init = []
	obj_init.append("jpg")
	obj_init.append("png")
	obj_init.append("bmp")
	obj_init.append("apng")
	obj_init.append("dicom")
	obj_init.append("jp2")
	obj_init.append("j2k")
	obj_init.append("tga")
	obj_init.append("webp")
	obj_init.append("tif")
	obj_init.append("gif")
	obj_init.append("ico")
	raster_formats = obj_init
	obj_init2 = []
	obj_init2.append("svg")
	obj_init2.append("otg")
	obj_init2.append("odg")
	obj_init2.append("eps")
	obj_init2.append("wmf")
	obj_init2.append("emf")
	obj_init2.append("wmz")
	obj_init2.append("emz")
	obj_init2.append("cmx")
	obj_init2.append("cdr")
	vector_formats = obj_init2
	all_formats = []
	all_formats.extend(raster_formats)
	all_formats.extend(vector_formats)
	
	for format_ext in all_formats:	
		input_file = os.path.join(templates_folder, f"template.{format_ext}")
		
		if not os.path.exists(input_file):
			continue
		
		is_vector_format = format_ext in vector_formats
		
		if is_vector_format:
			input_file = rasterize_vector_image(format_ext, input_file)

		output_file = os.path.join(templates_folder, f"{filter_name}_{format_ext}.png")
		print(format_ext)
		# explicit type casting from Image to RasterImage
		with as_of(Image.load(input_file), RasterImage) as image:
			do_filter(image)
			
			multi_page = None
			# if image implements an IMultipageImage interface
			if is_assignable(image, IMultipageImage):
				multi_page = as_of(image, IMultipageImage)
			
			if multi_page is not None and multi_page.page_count > 1:
				# for loop
				for_first_step = True
				page_index = 0
				for page in multi_page.pages:
					file_name = f"{filter_name}_page{page_index}_{format_ext}.png"
					page.save(templates_folder + file_name, PngOptions())
					os.remove(templates_folder + file_name)
					page_index += 1
			else:
				image.save(output_file, PngOptions())
				delete_file(output_file)

		if is_vector_format:
			delete_file(input_file)


def rasterize_vector_image(format_ext, input_file):
	output_file = os.path.join(templates_folder, f"rasterized.{format_ext}.png")
	with Image.load(input_file) as image:
		image.save(output_file, PngOptions())

	return output_file
	
	
def delete_file(file):
	if delete_output:
		os.remove(file)

# Run filters
binarize_fixed()
# binarize_bradley()
# binarize_otsu()