Display JPEG and TIF

[Juan Baron]

I am trying to show some images jpeg or tif using a layer raster, I
generate the wld and it leaves me the following error:

For the jpeg image:   drawJPEG(): Unable to access file. Only grayscale
JPEG images are supported.

For the tif image: Image handling error. Only colormapped and grayscale
images are supported.

Thank's