FYI: LZW compression in a TIFF file, regardless of whether it is a 1-Bit, 8-Bit, 24-Bit or 32-Bit file format, when used with FS / P3D Terrain SDK Resample, results in
longer compile times.
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NOTE: Final output source file format for TIFF Masks must actually be 8-Bit gray-scale; see:
http://www.fsdeveloper.com/forum/th...-scenery-achievable.440912/page-4#post-789447
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While this is not usually that noticeable with less-than 24-bit gray-scale files such as Blend Masks or Land-Water Masks, it is IMHO not necessary or desirable,
except when one is working with
very large source file sizes that 'risk' exceeding the 2-GB task session work-space and/or 2-GB output BGL size limit of Resample.
One may reduce visibility of gradient 'banding' in the 256 gray-scale Blend Mask by 'dithering' the image with
ex: Floyd-Sternberg techniques etc., but that would, like use of LZW compression, have no impact, IMHO, on what the OP is showing here.
https://en.wikipedia.org/wiki/Floyd–Steinberg_dithering
I believe what we may be seeing here is "excessive transparency", possibly by having used certain gray-scale values on the 'wrong' side of the mid-gray-scale point (RGB 127,127,127), such that the
ex: Blend Mask 'transparency' is beginning to allow the under-lying Water Class texture color to show through to the top of any over-lying custom photo-real aerial imagery contribution to the hydro polygon area rendering in FS at run time.
GaryGB