Se usi CompeGPS non dovresti avere problemi ad visualizzare gli ECW.
Se hai necessità di convertirli in altri formati ti consiglio la libreria GDAL ( open source ) che puoi scaricare gratuitamente da
http://fwtools.maptools.org/
Dopo l'installazione ,nella cartella bin trovi una utility ( gdal_translate ) che converte files da e in questi formati ( praticamente tutti i formati GIS ):
VRT: Virtual Raster
GTiff: GeoTIFF
NITF: National Imagery Transmission Format
HFA: Erdas Imagine Images (.img)
ELAS: ELAS
AAIGrid: Arc/Info ASCII Grid
DTED: DTED Elevation Raster
PNG: Portable Network Graphics
JPEG: JPEG JFIF
MEM: In Memory Raster
GIF: Graphics Interchange Format (.gif)
XPM: X11 PixMap Format
BMP: MS Windows Device Independent Bitmap
PCIDSK: PCIDSK Database File
PCRaster: PCRaster Raster File
ILWIS: ILWIS Raster Map
GMT: GMT NetCDF Grid Format
HDF4Image: HDF4 Dataset
PNM: Portable Pixmap Format (netpbm)
ENVI: ENVI .hdr Labelled
EHdr: ESRI .hdr Labelled
PAux: PCI .aux Labelled
MFF: Atlantis MFF Raster
MFF2: Atlantis MFF2 (HKV) Raster
BT: VTP .bt (Binary Terrain) 1.3 Format
IDA: Image Data and Analysis
JP2KAK: JPEG-2000 (based on Kakadu)
ECW: ERMapper Compressed Wavelets
JP2ECW: ERMapper JPEG2000
FIT: FIT Image
RMF: Raster Matrix Format
USGSDEM: USGS Optional ASCII DEM (and CDED)
Spero ti sia utile.
TB