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Converting RGB PDFs to CMYK PDFs via GhostScript CLI / Python (quality problem)

I am trying to achieve the following using a python script:
Read in an SVG design file (with images)
Manipulate the SVG file
Convert this to a web-ready PDF and a print-ready PDF
My problem is with the conversion of the RGB PDF to the CMYK PDF. An SVG with a 15MB photo in it will export as a 15MB RGB PDF, but then convert (using GhostScript) to a 3MB CMYK PDF. When trying ImageMagic, the resolution of the output PDF is determined by the density and I can't find how to keep the PDF's canvas size while setting the density.
So far, I have a script which reads in the SVG files and does some manipulation (add a logo using svgutils, change some text by scanning through the SVG text file). It then uses Inkscape to export the web-ready PDF (using "--export-area-page" and converting the text to paths) and a temporary PDF (using "--export-margin=X" where X is the bleed size, also converting text to paths). The temporary PDF is what I need, except it is RGB rather than CMYK. So, I then want to convert this file (Inkscape does not work with CMYK).
This is the function I am using to convert the file (it is setup with GhostScript and also I was trialling ImageMagick):
converter_program = "GHOSTSCRIPT"
def convertPDFtoPrintReadyPDF(pdf_in, new_filename=None, output_location=None):
global converter_program
if (new_filename == None):
new_filename = os.path.basename(pdf_in).replace(".svg", ".pdf")
if (output_location == None):
output_location = os.path.dirname(pdf_in)
output_file = output_location + "\\" + new_filename
argument_list = []
if (converter_program == "GHOSTSCRIPT"):
pdf_tool_loc = r'"C:\Program Files\gs\gs9.55.0\bin\gswin64c.exe"' # Added "c" at end for non-window version (command line)
argument_list.append('-o "' + output_file + '"')
argument_list.append(r"-sDEVICE=pdfwrite")
argument_list.append(r"-dUseBleedBox")
argument_list.append(r"-dQUIET")
argument_list.append(r"-dPDFSETTINGS=/printer")
argument_list.append(r"-dCompressPages=false")
argument_list.append(r"-dMaxInlineImageSize=200000")
argument_list.append(r"-dDetectDuplicateImages")
#argument_list.append(r"-dJPEGQ=100")
argument_list.append(r"-dAutoFilterColorImages=false")
argument_list.append(r"-dAutoFilterGrayImages=false")
#argument_list.append(r"-sCompression=Flate")
#breaks the code: argument_list.append(r"-sColorImageFilter=/Flate")
#argument_list.append(r"-r600")
argument_list.append(r"-dColorImageResolution=600")
argument_list.append(r"-dGrayImageResolution=300")
argument_list.append(r"-dMonoImageResolution=1200")
argument_list.append(r"-dDownsampleColorImages=false")
argument_list.append(r"-sProcessColorModel=DeviceCMYK")
argument_list.append(r"-sColorConversionStrategy=CMYK")
argument_list.append(r"-sColorConversionStrategyForImages=CMYK")
argument_list.append('"' + pdf_in + '"')
elif (converter_program == "IMAGEMAGICK"):
pdf_tool_loc = 'magick'
argument_list.append(r'convert "' + pdf_in + '"')
argument_list.append(r"-density 300")
argument_list.append(r"-resize 100%")
argument_list.append(r"-colorspace CMYK")
argument_list.append('"' + output_file + '"')
#convert tp_rgb.pdf -verbose -density 300 -colorspace CMYK tp_cmyk.pdf
argument_string = " ".join(argument_list)
subprocess.run(pdf_tool_loc + " " + argument_string, shell=True, check=True)
return output_file
Versions:
Python 3.8.10
GhostScript 9.55.0
ImageMagick 7.1.0-16

I found some GhostScript parameters to add to the conversion process:
argument_list.append(r"-dAutoFilterColorImages=false")
argument_list.append(r"-dAutoFilterGrayImages=false")
argument_list.append(r"-dColorImageFilter=/FlateEncode")
argument_list.append(r"-dGrayImageFilter=/FlateEncode")
argument_list.append(r"-dDownsampleMonoImages=false")
argument_list.append(r"-dDownsampleGrayImages=false")
So, the full argument list looks like this:
argument_list.append('-o "' + output_file + '"')
argument_list.append(r"-sDEVICE=pdfwrite")
argument_list.append(r"-dUseBleedBox")
argument_list.append(r"-dQUIET")
argument_list.append(r"-dDetectDuplicateImages")
argument_list.append(r"-dAutoFilterColorImages=false")
argument_list.append(r"-dAutoFilterGrayImages=false")
argument_list.append(r"-dColorImageFilter=/FlateEncode")
argument_list.append(r"-dGrayImageFilter=/FlateEncode")
argument_list.append(r"-dDownsampleMonoImages=false")
argument_list.append(r"-dDownsampleGrayImages=false")
argument_list.append(r"-dColorImageResolution=300")
argument_list.append(r"-dGrayImageResolution=300")
argument_list.append(r"-sProcessColorModel=DeviceCMYK")
argument_list.append(r"-sColorConversionStrategy=CMYK")
argument_list.append(r"-sColorConversionStrategyForImages=CMYK")
argument_list.append('"' + pdf_in + '"')
This turned the 15MB->3MB conversion into a 15MB->53MB.
It still needs some tweaking, but is now on the right track (I will update this answer if I get the process better).
I found the information thanks to this post: http://zeroset.mnim.org/2014/07/14/save-a-pdf-to-cmyk-with-inkscape/
Documentation is here (don't forget to delete the leading letter to search ("dColorImageFilter" to "ColorImageFilter"): https://www.ghostscript.com/doc/current/VectorDevices.htm

How to combine images from multiple folder into one with a counting number using python

I am really looking for a solution to this problem. I have been generating frames from a python code which i end up having into different folders as shown below,
**folder names** swimming_0, swimming_1, noswimming_0, noswimming_1.
swimming_0 noswimming_0
frame0.jpg frame0.jpg
frame1.jpg frame1.jpg
frame2.jpg frame2.jpg
swimming_1 noswimming_1
frame0.jpg frame0.jpg
frame1.jpg frame1.jpg
frame2.jpg frame2.jpg
What i expect:
In a single folder
swimming_0_0.jpg
swimming_0_1.jpg
swimming_0_2.jpg
swimming_1_0.jpg
swimming_1_1.jpg
swimming_1_2.jpg
noswimming_0_0.jpg
noswimming_0_1.jpg
noswimming_0_2.jpg
noswimming_1_0.jpg
noswimming_1_1.jpg
noswimming_1_2.jpg
The steps we need is that:
1. rename the images in each folder
2. combine the images
Python code used:
step1: renaming and adding incremental numbers
import os
folderpath = r'/swimming'
fileNumber = 1
for filename in os.listdir(folderpath):
os.rename(folderpath + '//' + filename, folderpath + "_" + str(fileNumber))
fileNumber +=1
Although this code works with my expectations for step 1 however I am looking for a more efficient way to do this. Could someone please help here.
Update:
It is also fine if we dont keep track of the filenames but atleast in that case i would expect the results to be.
swimming_0.jpg
swimming_1.jpg
swimming_2.jpg
swimming_3.jpg
swimming_4.jpg
swimming_5.jpg
noswimming_6.jpg
noswimming_7.jpg
noswimming_8.jpg
noswimming_9.jpg
noswimming_10.jpg
noswimming_11.jpg

Ok, so if you want to move files in separate folders to one you could try this:
First of you should have a structure like this:
from_here/
+ noswimming_0/
+ frame0.png
+ frame1.png
+ frame2.png
+ noswimming_1/
+ frame0.png
+ frame1.png
+ frame2.png
+ swimming_0/
+ frame0.png
+ frame1.png
+ frame2.png
+ swimming_1/
+ frame0.png
+ frame1.png
+ frame2.png
move_here/
script.py
script.py:
import os
from_path = os.getcwd() + '/from_here'
to_path = os.getcwd() + '/move_here'
for folder in os.listdir(from_path):
for file in os.listdir(os.path.join(from_path, folder)):
os.rename(os.path.join(from_path, folder, file), os.path.join(to_path, f'{folder}_{file}'))
This should now move the files from those separate folders to the one (obviously you could have more folders to move from or more files in those folders)

Use relative path to get all png files in python

Trying to retrieve all the paths of the pngs in different sub folders.
All sub folders are located within a main folder - logs.
pngs = []
for idx, device in enumerate(udid):
pngs += glob.glob(os.getcwd() + "/logs/" + device + "_" + get_model_of_android_phone(device) + "/" + "*.png")
File structure
logs/123456789_SM-G920I/123456789google_search_android.png
The values in bold will change. I have added in *.png for the changing pngs.
But how do i get the paths of the pngs when i do not have an absolute path to the png file?
Update
get_model_of_android_phone(device) is a method to get the following value here.
E.g. 123456789_SM-G920I
I am thinking to remove it cause it is not really working as intended. Would like to replace the method with something like *

You can use following in simplified way to get all file names:
for name in glob.glob(os.getcwd() + "/logs/**/*.png", recursive=True):
print '\t', name
When recursive is set, ** will matches 0 or more subdirectories when followed by a separator.
If you just want to make list, use the following code snippet :
pngs = glob.glob(os.getcwd() + "/logs/**/*.png", recursive=True)
It will return a list of all png file paths.
Reference : https://docs.python.org/3/library/glob.html

for idx, device in enumerate(udid):
path_device = os.getcwd() + "/logs/" + device + "_" + get_model_of_android_phone(device) + "/"
file_list = os.listdir(path_device)
pngs = [path_device+file_png for file_png in file_list if str(file_png).endswith(".png")]

ValueError: scandir: path too long for Windows

I am writing a simple Python script to tell me file size for a set of documents which I am importing from a CSV. I verified that none of the entries are over 100 characters, so this error "ValueError: scandir: path too long for Windows" does not make sense to me.
Here is my code:
# determine size of a given folder in MBytes
import os, subprocess, json, csv, platform
# Function to check if a Drive Letter exists
def hasdrive(letter):
return "Windows" in platform.system() and os.system("vol %s: 2>nul>nul" % (letter)) == 0
# Define Drive to check for
letter = 'S'
# Check if Drive doesnt exist, if not then map drive
if not hasdrive(letter):
subprocess.call(r'net use s: /del /Y', shell=True)
subprocess.call(r'net use s: \\path_to_files', shell=True)
list1 = []
# Import spreadsheet to calculate size
with open('c:\Temp\files_to_delete_subset.csv') as f:
reader = csv.reader(f, delimiter=':', quoting=csv.QUOTE_NONE)
for row in reader:
list1.extend(row)
# Define variables
folder = "S:"
folder_size = 0
# Exporting outcome
for list1 in list1:
folder = folder + str(list1)
for root, dirs, files in os.walk(folder):
for name in files:
folder_size += os.path.getsize(os.path.join(root, name))
print(folder)
# print(os.path.join(root, name) + " " + chr(os.path.getsize(os.path.join(root, name))))
print(folder_size)
From my understanding the max path size in Windows is 260 characters, so 1 driver letter + 100 character path should NOT exceed the Windows max.
Here is an example of a path: '/Document/8669/CORRESP/1722165.doc'

The folder string you're trying to walk is growing forever. Simplifying the code to the problem area:
folder = "S:"
# Exporting outcome
for list1 in list1:
folder = folder + str(list1)
You never set folder otherwise, so it starts out as S:<firstpath>, then on the next loop it's S:<firstpath><secondpath>, then S:<firstpath><secondpath><thirdpath>, etc. Simple fix: Separate drive from folder:
drive = "S:"
# Exporting outcome
for path in list1:
folder = drive + path
Now folder is constructed from scratch on each loop, throwing away the previous path, rather than concatenating them.
I also gave the iteration value a useful name (and removed the str call, because the values should all be str already).

How can i adjust my code to start with a new number?

import os
src = "/home/user/Desktop/images/"
ext = ".jpg"
for i,filename in enumerate(os.listdir(src)):
# print(i,filename)
if filename.endswith(ext):
os.rename(src + filename, src + str(i) + ext)
print(filename, src + str(i) + ext)
else :
os.remove(src + filename)
this code will rename all the images in a folder starting with 0.jpg,1.jpg etc... and remove none jpg but what if i already had some images in that folder, let's say i had images 0.jpg, 1.jpg, 2.jpg, then i added a few others called im5.jpg and someImage.jpg.
What i want to do is adjust the code to read the value of the last image number, in this case 2 and start counting from 3 .
In other words i'll ignore the already labeled images and proceed with the new ones counting from 3.

Terse and semi-tested version:
import os
import glob
offset = sorted(int(os.path.splitext(os.path.basename(filename))[0])
for filename in glob.glob(os.path.join(src, '*' + ext)))[-1] + 1
for i, filename in enumerate(os.listdir(src), start=offset):
...
Provided all *.jpg files consist of a only a number before their extension. Otherwise you will get a ValueError.
And if there happens to be a gap in the numbering, that gap will not be filled with new files. E.g., 1.jpg, 2.jpg, 3.jpg, 123.jpg will continue with 124.jpg (which is safer anyway).
If you need to filter out filenames such as im5.jpg or someImage.jpg, you could add an if-clause to the list comprehension, with a regular expression:
import os
import glob
import re
offset = sorted(int(os.path.splitext(os.path.basename(filename))[0])
for filename in glob.glob(os.path.join(src, '*' + ext))
if re.search('\d+' + ext, filename))[-1] + 1
Of course, by now the three lines are pretty unreadable, and may not win the code beauty contest.