Georeferencing

[DavidMcMillan1]

I have some tiff images that I imported into Acrmap.  I georeferenced them and turned them into a image service.  Now we re-scanned the same images in color and the pixel size is different.  How can I bring the new images in without having to georeference again.

Thanks,

Dave McMillan PLS

[SachinKanaujia]

David McMillan‌ One approach that should work is by writing a world file. Post Georeferencing you can export your raster and write a world file with georeferencing information. After this you should be able to replace the image. Make sure the extension remains the same.

[DavidMcMillan1]

How do I use the same .tfw file.  I have it in the same folder as the new un-referenced image.  Then when I bring it in it does not appear to use the world file.

[DavidMcMillan1]

Also my size of my original image is 13520 x 13711 pixels and the new image is 6764 x 6920 pixels.

Would that be a problem?

Thanks,

Dave

[MelitaKennedy]

Minimum you would need to change values 1 and 4 in the world file because the cell size has changed. Those values (same, but #4 is negative) identify how many meters or feet a pixel represents.

Is the origin the same? If not, you're definitely going to have to georeference the new images.

Melita

[larryzhang]

dave,

You georeferenced 'same' images; and then re-scan the same images (just different pixel) for re-georerancing.... To me, this practice is not recommendable, especially, in operation.

In fact, you can resample the georeferenced images to the desired pixel (coarse, i.e., 2 m   from 0.3 m) by the gp tool 'resample'...