GFXMerge is actually two plug-ins in one. The first takes selected layers from a source image and transfers them to a destination image, including layer masks. This is the Merge part of GFXMerge. Merges can be undone with a single Ctrl-Z in the destination image.
The second part of GFXMerge is the Split option. This feature takes the selected layers from a source image and creates a new destination image using only those layers and their masks.
Table of Contents
A tour of the GFXMerge dialog window
While one of the most useful plug-ins in the Graphics Muse Tools suite GFXMerge is also one of the simplest to use. The interface consists of a two tab notebook, one each for merging and splitting images. Each tabs page has a similar layout as the other.
The Merge Images tab provides source and destination image boxes. Initially these are used to display the layer names from their respective images. Later the destination box will show the layers added to it from the source image and can be used to reorder the layers - both old and new. Two option menus provide access to the available images (available means currently open). A white box runs the bottom of the window and is used to display status messages. Below this is a button for resizing the destination image Canvas, if needed.
The Split an Image tab looks similar, providing a source image box with a New Image Contents box. This box will hold the layers selected to copy from the source image and place in a new Canvas window. A single option menu allows you to choose the source image from which you will copy your layers for the new image. This tab, too, provides a status message box below the options menu.
Merging layers from a source image into a destination image is a straightforward process that is outlined in the following steps:
- Select the source image from the Source Image options menu.
- Select the destination image from the Destination Image options menu.
- Optionally choose to resize the destination image, if needed.
- Select the layers to merge from the Source Image box by clicking on the layer name.
- Click the Add button to add the selected layers to the end of the Destination Image list.
- Reorder the destination image layers by dragging the layer names up and down the list.
- Click the Apply button to merge the source layers into the destination image.
If the destination image is smaller than the source, either in width or height, then you'll be offered the chance to resize the destination Canvas so that the copied layers will fit properly. If you don't resize at this point you can choose to do so later when you flatten your image or merge visible layers using the Layers and Channels dialog.
Layers added to the destination image are positioned relative to their positions in the source image. This means that if the source layer was offset by 10% of the width and 10% of the height in the source image, it will be offset by 10% of the destination width and 10% of the destination height. These calculations are done after the destination is resized, if necessary.
When you apply your changes the destination image will be updated with the layers copied from the source image. Once applied, the changes to the destination image can be undone with a single CTRL-Z keystroke.
Note that layers that exist in the destination image initially are highlighted in yellow. These layers cannot be removed from the list or selected, but they can be dragged when reordering the layers. No changes are made to the source image - only the destination image is updated.
Splitting layers from an image
Splitting layers from an image is just like merging two images, except with this feature you'll be creating a brand new image window. The new window will be sized to fit the largest dimensions of the layers you've selected for copying.
Just like when merging, you can reorder the layers prior to applying your split changes by dragging the layer names around in the New Image list.
Note that you can't undo an image split because the new window won't go away with a CTRL-z operation. Just close the new window if it isn't what you wanted. The source image will remain unchanged. Also, there are no layers with yellow highlights in the New Image box because the new window starts without any layers. If the New Image list has no entries then clicking on the Apply button will have no effect.
- All new layers retain the layer name from the source image plus an additional tag of either "MERGED" or "SPLIT" to signify where these came from.
- You can select more than one layer at a time in the Source Image boxes, allowing you to Add multiple layers at once. Alternatively, you can select more than one layer in the Destination (or New Image) boxes to remove with a single click of the Remove button.
- The Destination Image and New Image boxes for Merging and Splitting, respectively, can be used to reorder the layers prior to clicking on the Apply button. Click on a layer name, holding down the left mouse button, and drag the layer name to its new location and release the mouse button. This trick can also be used even if you don't merge or split any layers! It's the hidden gem of GFXMerge - reorder multiple layers without having to wait for GIMP to render the changes.
- Since GFXMerge does not close automatically, you can reorder images again after you use the Apply button by selecting the updated image and simply dragging their layer names up or down the list.
- When you change either the source or destination image using the options menus the source and destination boxes will revert to their initial states. This is true for both the Merge and Split tabs.
- When you change tabs between Merge and Split, the changes made in either page will be reset to their initial states.
