#### Operator index > By section > Mosaicing [src]

These functions are useful for joining many small images together to make one large image. They can cope with unstable contrast and arbitrary sub-image layout, but will not do any geometric correction. Geometric errors should be removed before using these functions.

The mosaicing functions can be grouped into layers:

The lowest level operation is `vips_merge()` which joins two images together left-right or up-down with a smooth seam.

Next, `vips_mosaic()` uses search functions plus the two low-level merge operations to join two images given just an approximate overlap as a start point.

`vips_mosaic1()` is a first-order analogue of the basic mosaic functions: it takes two approximate tie-points and uses them to rotate and scale the right-hand or bottom image before starting to join.

Finally, `vips_globalbalance()` can be used to remove contrast differences in a mosaic which has been assembled with these functions. It takes the mosaic apart, measures image contrast differences along the seams, finds a set of correction factors which will minimise these differences, and reassembles the mosaic. `vips_remosaic()` uses the same techniques, but will reassemble the image from a different set of source images.

## Functions

- `vips_merge()`
- `vips_mosaic()`
- `vips_mosaic1()`
- `vips_match()`
- `vips_globalbalance()`
- `vips_remosaic()`
- `vips_matrixinvert()`
- `vips_matrixmultiply()`