JPG Quality in command-line Batch Conversion

[arber6]

Hi, I've recently started using the batch conversion feature from the command line, but I haven't been supplying the /jpgq switch. When I use the IrfanView application, I have quality set to 100.

My images seem to get converted with about an 80% quality (I did some manual saves in the GUI at various qualities and 80% gives about the same file size).

So, my question is this, does command-line usage ignore the Irfanview quality settings and default to 80 (or something around there), unless the /jpgq switch is supplied?

[Skippybox]

Command-line usage does not ignore the IV quality settings. If you definitively have the quality set at 100, then that setting will be used for the command-line. However, if that setting is changed at some point, then that new setting will be used.

If you don't actually save something using the setting you provide, the edited setting will not be retained. Try it and see. Edit the setting, cancel the operation, and recheck the setting. It will be what it was before. This is probably what is happening to you.

If you want to know for sure what the setting is, then either specify the /jpgq setting in the command-line or check the ini in section [JPEG] under Save Quality. Or just trust that you've have done it correctly in the program.

[arber6]

Sorry for not getting back sooner, but it took me a while to spot, what I tink, is the problem.
I'm specifying an ini file (that I created using the save-ini-file feature of Irfanview) in my command-line, and closer inspection of the specified ini file reveals that it doesn't seem to have any settings relating to JPG quality.
It seems that Irfanview fails to find any quality setting in the specified ini file, ignores the default ini file and so defaults to about 80.
I haven't tried adding the setting manually to my ini file, but I'm wondering whether this should be raised as a bug, not so much in relation to command-line usage per se, but in terms of incomplete settings being saved to an ini file, and thereby, unexpected results when using a specified ini file from the command line.

[Skippybox]

Ahh, specifying an alternate ini is a different story. Yes, if a pertinent setting is missing from your supplied ini, then the setting will come from the program's default values. In other words, not the program ini. Since the default JPG quality is 80, this is what you are encountering.

While you may think it should work the other way, that doesn't make it a bug. I think if it worked the other way around, it would be difficult to obtain a default set of values, because you would be forced to change every setting to counter the program ini. Remember, all ini files do not contain complete values, including the program ini. Only when a setting differs from that of the default values, does an entry generally get written. For instance, IrfanView will start without any ini at all. The same goes for your custom ini. Any values missing will take on that of the programs default set.

So, specify what you need in the custom ini or use an override switch. You might have an easier time if you work with the program ini, and make changes to that, so you know what to expect. Make a copy of the program ini and rename it as a backup. Then using the IrfanView or a text editor, change the values you want. Move the custom ini to its new location and restore the original ini. Remember, to work, ini files must be named i_view32.ini.