Hi,
Another thought.
If you replace the images and GPS points with time positions on a time line, the NeighborFinder can be used to find GPS point which has minimal time difference for each image.
Assuming that the format of datetime is "yyyymmddHHMMSS".
(1) Use a RasterExtractor to store each raster (image) data as an attribute.
(2) Replace each raster with a point on the time line by a VertexCreator.
X: datetime of the image, Y: 0
(3) Extract the coordinate (x, y) of each GPS point by a CoordinateExtractor.
(4) Replace each GPS point with a point on the time line by a VertexCreator.
X: datetime of the GPS point, Y; 0
(5) Add a NeighborFinder; send the (2) points to the Base port; send the (4) points to the Candidate port. Matched features will have the coordinate (x, y) of the closest candidate (GPS) point on the time line.
(6) Finally use a RasterReplacer to restore the original raster.
Alternatively, (assuming the rasters have unique ID attribute) you can use a FeatureMerger to merge the Matched features to the original images, instead of the RasterExtractor/RasterReplacer pair.
Takashi