This thread is old, but still number 1 when searching google for "geotiff arcgis javscript", so i thought I'd share how I accomplished it overlaying a geotiff into arcgis javascript is not possible with just the api. I used 2 other libraries to do it: seikichi/tiff.js · GitHub xlhomme/GeotiffParser.js · GitHub The way I did it was to load the file as an ArrayBuffer reader.readAsArrayBuffer(input.files[0]);
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