Batch Processing

Creating and Using Batch Operations

A batch operation can be as simple a converting a list of images to JPEG files for the web or printing them. Or, it can involve performing a complicated series of operations on a series of images and then saving them in another folder. The File Open transformation works in conjunction with other batch transformations (all of which are found in the Transformation menu under File). These transformations currently include:

Export -- outputs image files to a folder

Print -- prints image files

Slide Show -- displays images full screen in a slide show

These transformations simply pass their input image through to their output image. But, if a batch process is running, they also export, print or display their input image as well.

To batch process a series of images, you need to create an image tree that starts with a File Open transformation and includes one or more batch transformations. Optionally, you can include other transformations in between if you want to do additional processing on the images such as cropping, adding text or sharpening. The File Open transformation creates a new top-level image. After creating this new image, you can create additional transformations below it, typically ending with one or more Export, Print or Slide Show transformations. Once the image tree is set up, re-open the File Open transformation, select the images you want to process, and click the Run or Test buttons on the tool bar. One by one, each selected image is opened, and the image tree is recalculated. Since a batch process is active, this causes any Export, Print or Slide Show transformations to export, print or display their input images.

A Batch Status dialog box is displayed during batch processing. This dialog box displays the pathname of the file currently being processed, the batch operation being performed, and a thumbnail of the image currently being processed.

Clicking the Terminate Batch Process button stops the current batch process at the next transformation.

Breakpoints

You may need to manually adjust some settings during a batch workflow -- for example to adjust a cropping rectangle or do some cloning or speck removal. To accomplish this, set breakpoints on each transformation you want to be able to adjust and the batch workflow will pause at each breakpoint and display the transformation dialog box so you can modify its settings. Then click OK to resume the batch workflow or Cancel to terminate the batch process. In batch mode, there is no Apply button, and the image browser and main tool bars are disabled. As a convenience, you can use the keyboard shortcuts Enter or Esc instead of clicking OK or Cancel.

You can set a breakpoint on an image either by right-clicking its thumbnail in the Image Browser and selecting Toggle Breakpoint from the popup menu, or via the Edit/Toggle Breakpoint command from the main menu. If a breakpoint is set, the image thumbnail in the Image Browser will have a red outline. To delete all breakpoints, use the Edit/ Delete All Breakpoints command.

Example

Here is an example of a batch workflow that opens three files, pauses with a breakpoint to let you crop each one manually, and then saves the resulting image as a new file:

Note that all three files in the file list are shown as selected, but you can deselect any files you want to skip. To start the batch process, click the  button in the File Open dialog box. This will feed each file in the list, in succession, to the Crop transformation below it. Because a breakpoint is set on Crop (indicated by the red outline), processing will pause to let you specify the cropping rectangle manually. When you click OK, the cropped image is passed to the Export transformation which write it out as a file. If you click Cancel instead, the batch workflow is terminated and no more files are processed.

Multiple Batch Processing

Frequently, all you need to do is process a single list of files, but sometimes you may need to process more than one file at a time. For example, say you want to merge two sets of stereo image pairs and print them. Or maybe you want to open images in groups of four, merge them into a layout and export the result to a folder of image files. To accomplish tasks like these, you can use Multiple Batch processing which lets you operate on more than one file list at a time. It does this by reading one file from each list before recalculating the image tree.

If Picture Window detects that there is more than one File Open in the image tree having multiple files selected, it enables the Single Batch/Multiple Batch tool bar, which is otherwise grayed out.

In Single Batch mode, only the selected files in the current File Open are processed.

In Multiple Batch mode, all File Opens having multiple files selected are processed as a group, with the next file from each list being opened before the image tree is recalculated. Batch processing stops when any of the lists runs out of files. You will get a warning before batch processing starts if there are not the same number of selected files in each list. If you were merging left/right stereo images, for example, you might have two File Opens, one for the left images and one for the corresponding right images. It is important for both lists to be sorted so the correct images are combined -- you might be able to do this by sorting both lists if the files are named consistently or have consistent file dates. If your workspace includes File Opens you want to exclude from multiple batch processing, deselect all but one of the files in their file lists, and they will be passed over.

Differences between Batch and Normal modes

While Picture Window is running in Batch mode, it works a little differently.

The Image Browser, main tool bars and main menu are all disabled to prevent disturbing the batch process by changing the image tree while it is running.

Whenever a breakpoint is reached for a transformation, its Apply button is removed and OK and Cancel are used to continue or to terminate the batch process.

No progress indicators are displayed.

Tips

There is a separate setting in the color management settings dialog box that lets you specify an alternative value of the Ask on Mismatch setting that overrides the normal setting during the execution of a bath process. Asking about profile conversion every time a new file is opened can interrupt unattended batch operation. To avoid this, choose a different setting for the batch version of Ask on Mismatch.

As an aid in testing batch processes, you can insert a Bypass transformation (which basically just passes its input through to its output) and set a breakpoint on it. This causes batch execution to pause at the breakpoint so you can see the results of all the transformations up to the Bypass. Then, at the breakpoint, click OK to continue or Cancel to terminate.