JPEG to PNG with color replacement

main.py

from PIL import Image
import os

print("JPEG to PNG converter with Color replacement started.")

sourceDirectory = ".\source_images"
targetDirectory = ".\converted_images"

minColorValue = 235
maxColorValue = 255


def processImage(filename):
    print("Processing image '" + filename + "'...")
    img = Image.open(os.path.join(sourceDirectory, filename))
    img = img.convert("RGBA")
    datas = img.getdata()
    newData = []
    for index, data in enumerate(datas):
        replaceColor = True
        for i in range(2):
            replaceColor = replaceColor and minColorValue <= data[
                i] <= maxColorValue
        if replaceColor:
            if index - 1 >= 0 and index + 1 <= len(datas):
                for nI in range(index - 1, index + 1):  #nI = nearIndex
                    for i in range(2):
                        replaceColor &= minColorValue <= datas[nI][
                            i] <= maxColorValue

        if replaceColor:
            newData.append((255, 255, 255, 0))
        else:
            newData.append(data)

        # Debug output
        if index % 10000 == 0:
            print(str(index) + "/" + str(len(datas)))
    newFileName = os.path.splitext(os.path.join(targetDirectory,
                                                filename))[0] + '.png'
    img.putdata(newData)
    img.save(newFileName, "PNG")
    print("Done.")


# Iterate through files from source directory.
for filename in os.listdir(sourceDirectory):
    if filename.endswith(".jpg") or filename.endswith(".jpeg"):
        processImage(filename)
        continue
    else:
        continue