I've tried to make PNGExtra fairly simple to use, but for the full picture, here's the A B C of
installing and using the program and understanding the various features plus some tricks to improve your workflow.
The PNGExtra program consists of only one executable file called
PNGExtra1.exe. There are no system files, no configuration files, no help files, no changes needed to
the registry or other Windows components. As a result, PNGExtra doesn't even need an installation program!
Installation involves simply saving that one executable file directly onto your computer and it's ready to run.
The easiest location is onto your "Desktop" or to somewhere appropriate within your "Start Menu".
Un-installation is equally simple - just delete that one file.
More Advanced Installation:
Creating a program "Shortcut" will give a few additional startup options. The following example shows how I've
modified the startup options for my system:
- Save the executable file:
PNGExtra1.exe somewhere onto your computer, such as into the folder:
C:\Program Files\ (which is where most programs are stored). I've created a new sub-folder called:
C:\Program Files\PNGExtra\ specifically for this file;
- Using Windows Explorer, navigate to the folder where you saved the executable file;
- Right-click that executable file, then click:
Create Shortcut. This will create a shortcut named something like:
Shortcut to PNGExtra1.exe;
- Rename that shortcut to something meaningful (eg.
- Right-click that shortcut, then click:
- Change the entry:
Start In to point to the folder where you would normally want PNGExtra to start looking for files. (eg.
- Change the entry:
Shortcut Key to something easy to remember (eg.
- Click the button:
Change Icon and select either the small or large icon to suit your preference;
- Click the button:
OK to save the changes.
The customized shortcut can then be copied or moved elsewhere on the computer. For example, it can be copied either
to the "Desktop" or the "Start Menu".
With this shortcut, you could put any newly created PNG files into the "C:\NewPics" folder, press "CTRL-ALT-P" to
quickly fire up PNGExtra, press "Start Processing" to quickly process those files, then move the optimized PNG
files to their final destination. Easy!
PNGExtra Main Screen
What to Process:
The left side of the window shows the drives on the system plus the current folder.
Use the "Browse" button or double-click on the Drives or Folders to navigate to the folder to process.
The middle of the window shows the list of PNG files in the chosen folder (ie. files that end with ".png").
Click on any individual file for details of that file (date, size). Double-click on any individual file to process
just that one file.
The right side of the window shows the "Start Processing" button, totals of all files processed and totals of
those files that were actually optimized, plus various processing and log file options.
Overview of Usage:
The idea is to more or less work from left to right. Choose the drive you want to process, choose the folder,
then set any options and either click on the "Start Processing" button (to process all files) or double-click on
any individual filename (to process just that one file).
PNGExtra Log File
Using The Log File:
PNGExtra can create a log file, which is a simple text file containing the following details: Folder,
File Name, File Date, File Size Before, File Size After, Bytes Saved, Percent Saved,
plus any Errors encountered.
The log file, called
!PNGExtra_Log.csv, is located in the same folder as the files processed.
Using Windows Explorer, double-click on the log file to import it into a spreadsheet. Sorting the results by
either "Bytes Saved" or "Percent Saved" (especially in descending order) will very quickly highlight those files
for which PNGExtra has made the biggest savings.
• Analyse Only / Don't Modify:
Allows a "test run", which will show what savings can be expected without actually modifying the files. As
mentioned above, the Log File is useful for analysing the results.
• Process Sub-Folders Also: PNGExtra will also process any lower-level folders that it finds below
the chosen folder. For example, processing the "C:\My Documents" folder will also process the lower level
"C:\My Documents\My Images" sub-folder, plus anything else further below. A whole drive can be processed
in one pass using this option.
• Pause on Errors: When PNGExtra encounters any errors, it will pop up a dialog box showing the
error, allowing you to continue or to cancel further processing.
• Backup Original Files: When PNGExtra does modify a file, it will create a backup of the original
file. This will have the same filename but will change the file extension. For example, "123.png" becomes "123.old".
Backups are valuable for several reasons. Firstly, to compare the optimized file with the original file to verify
that the image is unchanged. Secondly, in the unlikely event that there is an error with the optimized file, the
original file is still available. Thirdly, to keep the original, unaltered file for archival purposes, as it may
contain data (such as a meaningful comment, Exif digital camera info, etc.) that could prove useful in future for
historical or legal reasons.
• Keep 8-bit Transparency: For 8-bit PNG files, this will retain any transparency.
This option was added because of the different way that 8-bit and 24-bit PNG files store transparency. In 8-bit
PNG files, transparency values are stored in a separate palette, which would otherwise be discarded as "extras".
By comparison, 24-bit PNG files store transparency within the image data, so it is always retained.
Log File Options:
• Log All Files Processed: Create a log entry for each file processed, even if the file was not
modified or if there were any errors processing. If there was already an existing log file, add the entries to it,
otherwise start a new log file.
• Log Files With Extras Only: Only create a log entry for those files that were found to contain
extras and that were successfully optimized without errors.
• Don't Write to Log File: Don't create a log file (although if one already exists, don't delete it).
• Remember All Options: Remembers all of the above options for the next time PNGExtra is run.
This creates a
TINY setting in the Windows registry (ie. there is no major change to the registry, so don't panic!).
For those interested, the setting is saved in the following key:
This registry key can be safely deleted, which is the same as un-ticking "Remember all options". Next time
PNGExtra is run, it will have reverted to the default settings.
The "Help" menu also contains a shortcut to go to the PNGExtra website. Note that this does
NOT communicate anything, private or otherwise; it simply points your browser to the site's address.
Typical PNGExtra Usage
Optimizing Existing PNG Files:
Typically, users have a "library" of all of the PNG files for their website sitting somewhere on a production
computer. It's a simple matter to navigate to that folder using PNGExtra and process all of the PNG files therein.
The optimized PNG files can then be re-uploaded to the website.
Optimizing Newly Created PNG Files:
When working on additions to a website, it's often a good idea to temporarily place any newly created PNG files
into a separate folder (eg. "C:\NewPics\"). This simplifies the task of optimization because PNGExtra can very
quickly process that one folder, after which the optimized PNG files can be uploaded to the website as well as
copied back to the image library.
Re-Optimizing PNG Files:
Unlike most other PNG optimization programs, PNGExtra can be run over the same PNG files
any number of times. This is because PNGExtra does not modify the image data in any way and thus will never
reduce their quality. If PNGExtra finds no "extras", those files will not be changed.
It's a good exercise to occasionally run PNGExtra over the whole of an image library to double-check that no files
containing "extras" have made their way into the library (eg. through simply forgetting to optimize, or restoring
an old version of a file). After re-processing the library, a quick check of the totals will show if any files
were optimized. The log file will then be invaluable for determining those files that need to be re-uploaded.