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#!/usr/bin/env python3
# -*- coding: utf-8 -*-
"""
Created on Tue Jul 21 10:05:07 2020
Example use of gsapi for various tasks.
@author: Michael Vrhel
"""
try:
import gsapi
except Exception:
print('Failure to import gsapi. Check shared library path')
raise
import os
ghostpdl_root = os.path.abspath('%s/../../..' % __file__)
print('ghostpdl_root=%s' % ghostpdl_root)
def run_gpdl(params, path):
instance = gsapi.gsapi_new_instance(0)
gsapi.gsapi_set_arg_encoding(instance, gsapi.GS_ARG_ENCODING_UTF8)
gsapi.gsapi_add_control_path(instance, gsapi.GS_PERMIT_FILE_READING, path)
gsapi.gsapi_init_with_args(instance, params)
end_gpdl(instance)
def init_gpdl(params):
instance = gsapi.gsapi_new_instance(0)
gsapi.gsapi_set_arg_encoding(instance, gsapi.GS_ARG_ENCODING_UTF8)
gsapi.gsapi_init_with_args(instance, params)
return instance
def run_file(instance, filename):
exitcode = gsapi.gsapi_run_file(instance, filename, None)
return exitcode
def end_gpdl(instance):
gsapi.gsapi_exit(instance)
gsapi.gsapi_delete_instance(instance)
# run multiple files through same instance
def multiple_files():
out_filename = 'multi_file_output_%d.png'
params =['gs', '-dNOPAUSE', '-dBATCH', '-sDEVICE=pngalpha',
'-r72', '-o', out_filename]
instance = init_gpdl(params)
run_file(instance, '%s/examples/tiger.eps' % ghostpdl_root)
run_file(instance, '%s/examples/snowflak.ps' % ghostpdl_root)
run_file(instance, '%s/examples/annots.pdf' % ghostpdl_root)
end_gpdl(instance)
# Extract text from source file
def extract_text():
in_filename = '%s/examples/alphabet.ps' % ghostpdl_root
out_filename = 'alphabet.txt'
print('Extracting text from %s to %s' % (in_filename, out_filename))
params =['gs', '-dNOPAUSE', '-dBATCH','-sDEVICE=txtwrite',
'-dTextFormat=3','-o', out_filename, '-f', in_filename]
run_gpdl(params, in_filename)
# Perform different color conversions on text, graphic, and image content
# through the use of different destination ICC profiles
def object_dependent_color_conversion():
in_filename = '%s/examples/text_graph_image_cmyk_rgb.pdf' % ghostpdl_root
out_filename = 'rendered_profile.tif'
image_icc = '%s/toolbin/color/icc_creator/effects/cyan_output.icc' % ghostpdl_root
graphic_icc = '%s/toolbin/color/icc_creator/effects/magenta_output.icc' % ghostpdl_root
text_icc = '%s/toolbin/color/icc_creator/effects/yellow_output.icc' % ghostpdl_root
print('Object dependent color conversion on %s to %s' % (in_filename, out_filename))
params =['gs', '-dNOPAUSE', '-dBATCH', '-sDEVICE=tiff32nc',
'-r72','-sImageICCProfile=' + image_icc,
'-sTextICCProfile=' + text_icc,
'-sGraphicICCProfile=' + graphic_icc,
'-o', out_filename, '-f', in_filename]
# Include ICC profile location to readable path
run_gpdl(params, '../../toolbin/color/icc_creator/effects/')
# Perform different color conversions on text, graphic, and image content
# through the use of different rendering intents
def object_dependent_rendering_intent():
in_filename = '%s/examples/text_graph_image_cmyk_rgb.pdf' % ghostpdl_root
out_filename = 'rendered_intent.tif'
output_icc_profile = '%s/toolbin/color/src_color/cmyk_des_renderintent.icc' % ghostpdl_root
print('Object dependent rendering intents on %s to %s' % (in_filename, out_filename))
params =['gs', '-dNOPAUSE', '-dBATCH', '-sDEVICE=tiff32nc',
'-r72', '-sOutputICCProfile=' + output_icc_profile,
'-sImageICCIntent=0', '-sTextICCIntent=1',
'-sGraphicICCIntent=2', '-o', out_filename,
'-f', in_filename]
# Include ICC profile location to readable path
run_gpdl(params, '../../toolbin/color/src_color/')
# Distill
def distill():
in_filename = '%s/examples/tiger.eps' % ghostpdl_root
out_filename = 'tiger.pdf'
print('Distilling %s to %s' % (in_filename, out_filename))
params =['gs', '-dNOPAUSE', '-dBATCH', '-sDEVICE=pdfwrite',
'-o', out_filename, '-f', in_filename]
run_gpdl(params, in_filename)
# Transparency in Postscript
def trans_ps():
in_filename = '%s/examples/transparency_example.ps' % ghostpdl_root
out_filename = 'transparency.png'
print('Rendering Transparency PS file %s to %s' % (in_filename, out_filename))
params =['gs', '-dNOPAUSE', '-dBATCH', '-sDEVICE=pngalpha',
'-dALLOWPSTRANSPARENCY', '-o', out_filename, '-f', in_filename]
run_gpdl(params, in_filename)
# Run string to feed chunks
def run_string():
size = 1024;
in_filename = '%s/examples/tiger.eps' % ghostpdl_root
out_filename = 'tiger_byte_fed.png'
params =['gs', '-dNOPAUSE', '-dBATCH', '-sDEVICE=pngalpha',
'-o', out_filename]
instance = gsapi.gsapi_new_instance(0)
gsapi.gsapi_set_arg_encoding(instance, gsapi.GS_ARG_ENCODING_UTF8)
gsapi.gsapi_init_with_args(instance, params)
gsapi.gsapi_run_string_begin(instance, 0)
with open(in_filename,"rb") as f:
while True:
data = f.read(size)
if not data:
break
gsapi.gsapi_run_string_continue(instance, data, 0)
exitcode = gsapi.gsapi_run_string_end(instance, 0)
end_gpdl(instance)
return exitcode
# Examples
print('***********Text extraction***********');
extract_text()
print('***********Color conversion***********')
object_dependent_color_conversion()
print('***********Rendering intent***********')
object_dependent_rendering_intent()
print('***********Distillation***************')
distill()
print('***********Postscript with transparency********')
trans_ps()
print('***********Multiple files********')
multiple_files()
print('***********Run string********')
run_string()
wait = input("press enter to exit")
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