defectivejunk (Entries tagged as programming)

Checking python images to see if they're grayscale

nospam@example.com (NN) — Mon, 30 Mar 2009 21:29:12 -0400

Long story short, I need to check an entire folder of images to see if they're grayscale. Here's a python script I just wrote that will do that, and output the results to a timestamped log file. I added some comments to explain how it works.

graycheck.py

from PIL import Image

import ImageChops

import os

import string

from time import strftime



def main():

    subdir = 'C:\\pathtoimages\\'

    diffdir = subdir + 'diff' # output directory if you want to save the results

    badFiles = []

    

    for subdir, dirs, files in os.walk(subdir):

        if subdir != diffdir: #only check the main dir

            for file in files:

                if string.upper(file[-3:])=="JPG": # jpegs only

                        im = Image.open(file)

                        imGray = im.convert("L") # convert the original jpeg to grayscale and keep a copy



                        # need to convert back to RGB, but only if the original file wasn't already in mode L

                        if im.mode == "RGB": 

                            imGray = imGray.convert("RGB")



                        # get the difference of the original image and the converted grayscale

                        # if the original was grayscale, there's no difference, so output will be entirely black

                        output = ImageChops.difference(imGray, im)



                        i = 0

                        

                        for color in list(output.getdata()):

                            if color != (0,0,0): # check RGB black and single black value

                                if color != 0:

                                    # Image is not grayscale, for we found a difference

                                    i=i+1

                                    print i, color

                                    break                

   

                        outputFile = diffdir + "\\" + file[:-4] + "_Diff.jpg" # output dir plus filename only plus an extension



                        if i==0: # image is all black, could not be blacker

                            badFiles.append(file)

                            # output.save(outputFile) # uncomment to save the results as an image - though it should be a solid black file



    # print badFiles # uncomment to see the results



    logfilename = strftime("%Y-%m-%d_%H-%M-%S") + ".txt"

    logfile = open(logfilename, "w")

    

    for badFile in badFiles:

        logfile.write(badFile + '\n')



    logfile.close()

                        

if _name_ == '_main_': 

     main()

If you desire me to release this under a license, consider it released under the MS Public License.

Python 1

nospam@example.com (NN) — Sun, 20 Jul 2008 21:34:30 -0400

Despite my misgivings, I'm going to attempt to learn Python. I bought Learning Python. I'm already tired of the pointless Monty Python refs.

i kill you scum

nospam@example.com (NN) — Wed, 09 Jul 2008 08:07:10 -0400

It's going to be a great day when it's 8:05 and I already want to kill someone.

The following query will emulate a

SELECT emp_id,lname,fname FROM employee LIMIT 20,10

That says, give me 10 records starting at record 21. So what will be returned are rows 21-30. This is used heavily in web-based apps so you can do recordset paging.

No no no no no no no NO NO NO NO NO NO NO NO NO NO!!!

This is NOT HOW RELATIONAL DATABASES WORK. There is NO guarantee AT ALL that you will get the rows back that you're expecting. Unless stupid ass MySQL actually does this, in which case it's even a worse, shittier database system than I realized. (and honestly, any db that doesn't support stored procs is already pretty low in my book.)

noooo

nospam@example.com (NN) — Tue, 29 Apr 2008 16:40:45 -0400

OK, I just came up with something evil. But, I like it because it saves doing that extra assignment every time

StringBuilder qs = new StringBuilder(); bool firstKey = true; foreach (KeyValuePair kvp in param) { qs.AppendFormat("{0}{1}={2}", (firstKey & !(firstKey = false) ) ? String.Empty : "&", kvp.Key, kvp.Value); }

nullable

nospam@example.com (NN) — Fri, 11 Apr 2008 13:47:42 -0400

Why no "??=" operator in C#? Anyway, it's not like I can Google it. Maybe there is one, or some reason there isn't.

More insane code

nospam@example.com (NN) — Thu, 03 Apr 2008 09:42:56 -0400

{
if (Checked)
Checked = false;
}

C#

nospam@example.com (NN) — Tue, 01 Apr 2008 08:56:23 -0400

One thing I just absolutely do not understand is using properties vs public members. If all you're doing is { get; set; }, then how is that different from just using a public variable? Because it makes you feel better, like you're not exposing a public variable? Maybe there's some difference I just don't recognize or know about. But, whatever.

hourly wtf

nospam@example.com (NN) — Mon, 24 Mar 2008 13:44:12 -0400

Drives me crazy when people create objects just to use them once, and don't even change the value of it that time. Especially when the thing goes out of scope immediately afterwards.

For example.

{ string message = "Error: user is dumb"; Textbox1.Text = message; } return;

WHY DO THIS. WHY. IS IT TO HASTEN MY INEVITABLE ANEURYSM. IS IT. BECAUSE THAT'S WHAT IT SEEMS LIKE. JUST SHOOT ME IN THE FACE INSTEAD. PLEASE. AT LEAST THAT'S MORE HONEST.