Missing pixels on conversion to 8-bit

Y_Chau — Tue, 09 Jan 2024 08:17:14 GMT

Hello

I am converting images from 4-band 16-bit to 3-band 8-bit. Reason is to reduce size and since these are not for any scientific analysis, therefore 3 bands and 8-bit is enough.

I use 2 tools to achieve this. First "Make Raster Layer" to get 3 bands out of 4 and then "Copy Raster" to convert 16-bit to 8-bit. "Make Raster Layer" gives me a temporary layer which looks good, no missing pixels here.

After running the "Copy Raster" tool I get the 8 bit images and I see holes in them in dark shadow areas. I use below settings:

Output Raster Dataset: .TIF
Ignore Background Value: Blank (Blank is default. Making it 0 doesn't make any difference)
NoData Value: 0 (0 is default as in parent image)
Pixel type: 8-bit unsigned
Scale Pixel Value: Checked (Unchecked produces a blank white image)
Compression: JPEG

Rest all parameters are default. Its obvious that the lower values are being converted to zero as the data is rescaled from 16 to 8-bit. How can this be avoided so that there are no NoData pixels inside the image?

@VinayViswambharan can you help?

Sincerely

Re: Missing pixels on conversion to 8-bit

MetralAlexis — Wed, 22 Apr 2026 14:27:49 GMT

For the ones finding that post : set the no data parameter to -1 and it will do the trick (default is 0)

topic Missing pixels on conversion to 8-bit in ArcGIS Pro Questions

Missing pixels on conversion to 8-bit

Re: Missing pixels on conversion to 8-bit