Batch Conversion

Batch conversion is used for applying various graphical operations to an image, or set of images. The functionality is the same as NConvert, except controlled via the XnView GUI rather than the command line. A large number of functions are available and multiple operations can be configured and applied in one step. It is also easy to save a script of the configured functions, which facilitates convenient re-use. Many of the functions have configurable parameters.

To apply batch processing, select the files that you wish to process using the browser view of XnView, then click the 'convert' button from the toolbar (or 'Batch Processing' from the edit menu or the right-click menu). This will bring up the batch processing window with your selected files listed. You can also add or remove files from the list at this point, though it's not usually necessary.

The batch processing window has two tabs - 'General' and 'Transformations'. The window opens on 'General' and there are a couple of important options you will want to pay attention to here. Firstly, if you want to retain your original images (recommended, because you can't undo most of the functions once they're done), make sure you're either outputting into a different directory, or else you have the 'rename' option selected in the 'Overwrite' field. Secondly, select the desired output file type. This is a very useful transformation in itself and may even be all you want to do in some cases.

After sorting that out, select the 'Transformations' tab. This is where all the interesting stuff is. If you fully expand out the list (click on the +'s), you'll see a large list of functions. In order to apply any of these to your images either just double-click, or else single-click it and then click the 'Add' button. The name will be copied into the right-hand box, which contains the list of functions that will be subsequently used. If the function has variable parameters (not all do), then they will be displayed in the 'parameters' box, from where you can set the values. If you select something by accident or just change your mind, click it in the right-hand box and select 'remove'

You'll notice you can apply several processing steps at once. There's probably a practical limit to how many are useful, because applying a lot in one go can take a while. Also the more functions you apply at once, the less predictable the result. If you want to do lots, you may have more success applying the changes in stages.

The effect of each of the functions is detailed here:

Convert

Convert to Binary
Convert to Colours
Convert to Greyscale
Convert to True Colours

Image

Add Alpha
Add Text
Auto Crop
Canvas Resize
Clean Metadata
Crop]]
Extract Channel
Flip Horizontal
Flip Vertical
ICC convert
Lossless rotation
Replace color
Resize
Rotate
Set DPI
Watermark

Map

Align histogram
Auto contrast
Auto levels
Brightness
Colour Balance
Conbright
Contrast
Equalize
Gamma
Gammasat
HLS
Levels
Logarithmic Lut
Negative
Normalize
Normalize Ex
Posterize
Sepia
Shadow/Highlight
Solarize
Swap Component

Filter

Average
Blur
Edge detect Heavy
Edge detect Light
Edge detect Medium
Emboss
Emboss More
Emboss Detail
Enhance Edges
Enhance Focus
Focus Restoration
Gaussian Blur
Maximum
Median Box
Median Cross
Minimum
Sharpen
Soften

Noise

Add gaussian noise
Add laplacian noise
Add poisson noise
Add uniform noise
Reduce noise

Misc.

3D border
De-interlace
Drop Shadow
Lens
Mosaic
Oil Painting
Shear
Slice
Spread
Swirl
Tile
Waves