When you need to apply the same action to multiple photos, digiKam’s batch processing capabilities can come in rather handy. And the photo management application provides different ways to apply actions to a photo batch in one fell swoop.
For starters, you can perform certain actions on all photos in a specific album. To do this, right-click on the desired album, and choose the action you want from the Batch Process context menu. The actions available in the menu include Image Effects, Recompress Images, Resize Images, DNG Converter (lets you convert RAW files into the DNG format), and Batch RAW Converter (allows you to process the RAW files using the Batch RAW Converter tool).
For more serious batch processing, you should use the dedicated Batch Queue Manager tool. Using it, you can set up rather advanced processing profiles and manage multiple queues. To add selected photos to the Batch Queue Manager, choose either Image » Add to Current Queue (alternatively, use the Ctrl+B keyboard shortcut) or Image » Add to New Queue (or press Ctrl+Shift+B). This opens the Batch Queue Manager and adds the selected photos to an existing or new queue. To specify the actions you want to perform on the photos in the queue, pick the desired tools from the Base Tools section, and specify the settings for each tool in the Tool Settings pane. The File Renaming section in the Queue Settings pane lets you specify a renaming rule to apply to the modified photos. This can help you to differentiate between the processed photos and their originals.
While there are many ways to protect your photos from unauthorized use, watermarking still remains the simplest and probably the most effective technique that can help you to identify you as the creator and make it difficult to use your works without permission.
Although digiKam supports watermarking, this feature is hidden so well that you might not even realize that it’s there. This is because the watermarking function in digiKam is tucked under the Batch Queue Manager tool which you can use to watermark multiple photos in one go. Here is how this works in practice. Choose Tools | Batch Queue Manager (or press the B key) to open the Batch Queue Manager tool. Drag the photos you want to watermark from a digiKam album onto the Queues pane to add them to the current queue. Click on the Base Tools tab in the Batch Tools Available pane and double-click on the Add Watermark tool to add it to the Assigned Tools pane.
digiKam can use text or images as watermarks, and you can choose the desired watermark type in the Tools Setting pane. If you want to use the Image type, make sure that you already have a graphics file handy. Specify then the available settings such as Placement, Size, and Margins. Next, select the target folder in the Target section of the Queue Settings pane. In the Behavior section, you can specify what the system should do if it detects a file with the same name as the processed one in the target folder. You can either choose to overwrite the existing file or rename the processed file before saving it. You can also use the options available in the File Renaming section to specify a renaming rule to automatically rename the processed files.
Once you are satisfied with the settings, hit the Run button, and once digiKam’s finished, you’ll find the watermarked photos in the target folder.