Batch Conversion and Resizing of Images

The batch features of Irfan View are very powerful, but easy to use. Be very careful if opting to overwrite files though, as you can very quickly destroy your original images (>_<). You can also use the batch feature to rename images (and other file types).

1. Select Batch Conversion/Rename from the file menu (or press B) to open a dialogue box like that below. Browse to find the files you wish to convert, and select them in the file list window.

2. Click on Add to add them to the Input file list.

3. Browse to choose the Output directory, or click on the "Use this directory as output" to use the input directory as the output directory too.

4. Choose the output format from the dropdown list and click the Options button to view the available options for that file format.

For JPG image output you can choose the quality. A value of 50 gives decent results for most photos. Use a value of 75 or more for images having sharply contrasting areas of colour.

"Save as progressive" makes the image draw more quickly on the web.

5. Click the Set advanced Options button to display this dialogue box.

Here you can change many aspects of the image. I have opted to resize my images to a width of 400 pixels and to preserve aspect ratio. By leaving the height blank they will be resized to whatever height is necessary to retain the aspect ratio.

Check "Use Resample function" for best quality.

As you can see, there are lots of other options for rotating, flipping, adjusting, and recolouring images.

In the miscellaneous section check "Overwrite existing files" if you are converting to JPG. The Tiff files won't be overwritten, only JPG files of the same name if they exist.

6. Click on OK to accept the advanced options, then click on Start in the first dialogue box to start the conversion process. You will see a progress report like that on the right.

It will generate errors if the requested operation could not be completed, and warnings if files have been overwritten as requested.

Batch Renaming of Images

1. The same batch process dialogue box (B) is used to rename images too. Not only images, in fact, but any file types can be renamed.

2. Browse to the directory containing the files you want to rename, select them in the file list window, and add them to the Input files list.

Select "Batch Rename" and enter a file name pattern, or click "Set rename options" for more options. Click the Start button to rename the selected files. You will get a similar progress report to that illustrated above, telling you whether or not the operation has been successful.

The Set rename options dialogue box allows you to set a starting number other than 1 for the file name suffix (or prefix).

Click on Help for more advice and options, e.g.

"Please be very carefully when you use rename and first test your options with dummy files; batch rename can be very powerful = dangerous! Using bad name pattern, combined with options like Rename-Move original/input files and/or Overwrite existing files, you can, under special circumstances, remove all input/original files! Please do not use these options, until you REALLY know what you are doing. "

Finally, and a Word of Warning

Renaming and Conversion of images can be combined in a single operation.

In the Batch Process dialogue box, select "Batch conversion - Rename result files." Both operations will be performed in one operation.

While you're learning to use this powerful feature, don't be tempted to overwrite files unless they are unimportant or backed up on CD. Advanced options that you used previously may still be in force, and you may not get the intended result unless you check all the options carefully.