PNGExtra - Troubleshooting
PNGExtra will handle most problems, such as corrupt PNG files, disk errors and so forth. This page lists these
common errors plus some of the less obvious problems and their solutions.
Corrupt or Invalid PNG Files:|
PNGExtra is extremely careful when handling PNG files whose contents are corrupt or invalid. Any errors will be
displayed and the file will not be processed.
Some people mistakenly believe that an image in a different image file format can be converted to the PNG file
format simply by renaming the file (eg. renaming
ABC.PNG). However, changing the filename does
NOT change the file contents, so the data within the file will not be in the correct PNG format.
As above, PNGExtra will consider such a PNG file to be corrupt because the data will not follow the correct format.
PNGExtra will not try to identify what other type of file it "might be". Instead, it will simply skip that file.
Truncated PNG Files:|
A PNG file that has been cut short can easily occur when downloading images from the Internet. For example,
pressing "Esc" on the browser before an image has completely downloaded will create a truncated PNG file. PNGExtra
will show a warning and will still try to optimize such a file, but will make no attempt to properly terminate the
chopped off portion.
PNG Files With "Read-Only" Attribute:|
Windows allows any file to be tagged with a "Read-Only" attribute in order to prevent such files being modified.
PNGExtra will respect that attribute and will not attempt to process such a file.
PNG Files From CDs or DVDs:|
CDs and DVDs normally can't be written to directly without special CD or DVD "Burning" software. This means three
If files on a CD or DVD need to be processed with PNGExtra, they should firstly be copied to a hard drive, then
the Read-Only attributes need to be reset. Consult the Windows "Help" for details on how to clear the read-only
attributes of any such files.
- PNGExtra does not contain any such "Burning" capabilities, and therefore cannot process PNG files directly on a
CD or DVD.
- All files on CDs and DVDs (not just PNG files) are automatically given a "Read-Only" attribute, which as explained
above means that Windows is indicating that the file can not (or should not) be modified. This is a further reason
preventing PNGExtra from processing PNG files directly on a CD or DVD.
- When files are copied by Windows, the file attributes are normally copied as well. If PNG files are copied from
a CD or DVD to a hard drive, they will inherit the Read-Only attributes. Once again, PNGExtra will not be able
to process those PNG files.
Disk Space Errors:|
It's possible to run out of disk space whilst optimizing, especially if the option:
• Backup Original Files is selected, as some disk space will be consumed for every
single PNG file that is optimized.
If this happens when processing an individual file, PNGExtra will simply show a disk space error and stop.
If it happens while processing a whole library of files, PNGExtra will quit processing the current file but will
nonetheless attempt to keep running, the theory being that enough space may still be available to optimize some
of the remaining smaller PNG files.
Errors During Batch Processing:|
PNGExtra's greatest strength is that it is designed to run over a whole library of PNG files, often called "Batch
Processing". In order to find out about any errors without having to pause for each and every one, do the following:
If PNGExtra does find any errors, processing will proceed without stopping. Once completed, examine the log file
for a brief description of any errors found.
- Un-tick the error option:
• Pause on Errors;
- Select the log file option:
• All Files Processed.