---

 

Combine filters

The smash-together factory. If you want to combine several images to one, these are the filters to use. You can fade images into each other and even create a piece of celluloid film...

Depth merge

This is a very nice tool for combining two images.This is done with the help of two map images. The maps should be grayscale images (so you can control the outcome better). An example This example will hopefully make matters more clear: Take two images of equal size. Then create two new empty images with the same size as the original images.

• In one of the new images, take the blend tool and blend from black in the top left corner, to white in the opposite corner. For the other grayscale image, do the opposite. Black is bottom right and white is top left.
• Now, bring up the Depth merge dialog. Set Overlap to 0, set Offset to 0 and Scale1 and 2 to 1.000. Use one of the first opened images as Source 1, and the other one as Source 2. Use the first grayscale image as Depth Map to source 1, and the other one as map to source 2. Now the two images will get combined and a sharp border will appear diagonally from the to right to the bottom left.

Why? Well, the plug-in looks at both map images, and compares every pixel. The map with the darkest pixel will win, and the source to that map will get to show its image pixel. When we created our grayscale images, there was a clean line going diagonally Top Right to Bottom Left where the outcome flipped from one map to the other. Now when you understand the basics, you can create all kinds of maps.

Let's see what the slides can do for us. As in you saw in our example, there was a sharp border between the images. This was because the Overlap was set to zero. If we slide it up a bit, you will see that the border will be get more fuzzy and transparent. This is the variable you use to get soft transitions. Offset changes the darkness value of your maps. If you slide it to a negative value, the map to source 1 will get darker and therefore get more of the outcoming image. If you slide it to positive, the other map will get darker and get more of the outcoming image. The slides Scale 1 and Scale 2 make map 1 respectively map 2 darker or lighter. They have the same effect as Offset, but they are more sensitive to the touch.

Film

This plug-in creates a film celluloid of two or more images. This is a nice special effect, and I bet that you have seen something like this before in magazines or papers.

How to

The user interface is quite simple. In the image selection dialog you have a view of all available images. You just click Add, to use it in your film. On film shows the pictures on your film. To change the order of the pictures, you have to add and remove pictures so they will come in the order you want. Height is the height of the outcoming film. Color is the film color (black). The plug-in will automatically adjust your images so that they will fit. Numbering lets you specify a start number on the roll, and the Font (warning! - you have to have the font installed), color is the number color in your film (orange). Both the color on the film itself (usually black though) and the color of the numbers can be changed by clicking on them. Check the at top and at bottom if you want numbers there, otherwise uncheck.

Fuse

This plug-in creates a new image from tiles of one or several input images. You can use this filter in two ways:

You can use the target image as a template. This will result in an image that looks like a mosaic or cubist version of the original image, and where the mosaic stones or cubes consist of pieces of the input images (a little like modernist collage art where you create a composite image by cutting and pasting pieces of a newspaper). You can also create a new shape by fusing one or more images. This filter uses associative image reconstruction, meaning that it will search out pieces that match where they overlap, thus creating a pattern with more or less "solid objects" in it. The new pattern is a random mix of matching tiles from the source images, with a direction tendency towards the centre of the image.

If we take a look at the Fuse dialog, you'll find a window at the top of the dialog with a list of available images (Indexed images are not accepted). You can select one or all of the images in this list by mouse-clicking, click again to deselect.

Note, that the image you opened Fuse from is not used in the fusing process unless you select it in this menu or check the Use target as template button.

Parameters

The parameters list starts with Tile Size, which controls the size in pixels of the square tiles. Small tiles produce smoother images, but makes the operation very slow.

Overlap determines by how many pixels the selected tiles should overlap in the fused image. If Overlap is too low, you'll get small black gaps in the composite image, and it it's too high it'll slow down the process a great deal. The recommended amount is somewhere between a quarter and a third of the tile size.

Search time refers to how long the filter should search for the tile that best fits the overlap. Search time also slows down the process, but results in a smoother output. When you check Use target as template, Fuse has to determine what's most important - to find a tile that matches the template, or a tile that matches the overlap. If you set the Template Weight slider high, you'll get a good representation of the target image, but the image will look much more "cubist" than a fused image without template (but with the same parameter value). If you set the Template weight lower, you'll get a smoother image, but it will not bear as much resemblance to the template image.

The Gimp User Manual
Last modified: 19 May 1998