Resize or convert multiple images to a different format automatically

Begin by visiting the Irfanview website. Click the Download link on the left-hand side and click to be transferred to one of the sites that hosts the Irfanview download – we clicked the top one. Click the Download Now button to begin the download and, if the File Download Security Warning dialogue box appears, click Save and choose a location for the downloaded file. Firefox users should select Save File to save the download to Firefox’s default download folder. When the small installation file has downloaded, double-click it and follow the installation wizard. We suggest choosing the default values, but on the fourth screen you can decline the Google Chrome and/or Google Toolbar installations by removing the ticks from the boxes. Click Done when finished and Irfanview will launch.

Irfanview supports all popular image formats, but before starting it’s a good idea to open an example of one of the images that are going to be edited – just to check that Irfanview can do so. Click File, Open and browse to the image file. A preview of the selected image should be visible when it is selected, along with other technical information (ignore the small picture of a panda, that is just a quirk of Irfanview). Click Open to ensure it loads. Pressing the D key closes the file, although there will be no warning to save it if it has been altered.

Press the B key (or click File, then Batch Conversion/Rename) to open the batch-processing dialogue box. Irfanview has three types of batch operation, shown as radio buttons in the Work As section at top left. Batch conversion converts files to a different image format (in our example, we will convert JPEG images to the TIFF type). Batch rename changes the name of files according to a specified formula, and ‘Batch Conversion – Rename results files’ does both of these at the same time. We will use this third option, so click its radio button.

In the file browser window at the top right, navigate to the folder containing the images to be edited. To only show graphics files of a particular type, choose the type from the ‘Files of type’ dropdown menu. Select a file (or multiple files by holding down Shift or Control as you click) and click the Add button to add it to the Input Files window below, or click Add All to add all matching files in the folder (if there are subfolders that need to be included, click the box labelled ‘Include subdirectories’ before clicking Add All).

By default, Irfanview renames files to ‘image0001’, ‘image0002’ and so on. We want to use the original file name plus a four-digit sequential number, so in the Name Pattern box replace ‘image####’ with ‘$N####’. $N is a special symbol that tells Irfanview to use the original file name, and each # symbol represents a single number (to see all renaming options, click the Options button next to the Name Pattern box, then click Help). Now choose the target file format (TIFF in our case) from the dropdown menu. Click Options to choose advanced settings for that format if needed.

The box labelled ‘Output directory for results files’ shows where files will be saved. Click Browse to change this, or click the ‘Use Current (“look in”) directory’ button to use the folder shown in the file browser window. Tick the ‘Use advanced options’ box in the Output format section and click the Advanced button. Tick the Resize box, then click ‘Set new size as percentage of original’. Type 50 in the Width box and the same into the Height box. Click OK, then click Start Batch. A progress window appears, and when complete click Exit Batch, or Return to Batch to perform more conversions.