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Forest
566 post(s)
#10-May-18 06:08

I have put an image in a geopackage also saved the same image to ECW. The geopackage is about 3 times larger than the original png image and the ECW image is about half the size. Is there a choice of encoding for image tiles within a geopackage to reduce the size of the geopackage? I would like to use them on mobile devices which can't understand ECW images.

adamw


7,903 post(s)
#10-May-18 15:58

We don't currently allow specifying the format / conversion options for tiles in GPKG, but this is on the list. The options are going to be JPEG, PNG, WEBP, plus compression levels.

StanNWT62 post(s)
#10-May-18 18:57

Hi Adam,

Ever thought of trying to include Microsoft's new High Efficiency Image Format (HEIF)? Since Manifold is so Microsoft intergrated, perhaps it's something to think about.

Granted none of the GIS I work with has this feature, nor any of the current versions of the graphics programs I use have it.

I would also recommend using JPEG2000, as its an ISO standard and offers lossy or lossless compression with compression level support. JPEG2000 is not as fast as ECW in my experience but since it's an ISO standard it's likely to gain favor among some users. I still love the speed of ECW files, yes I'm an ER Mapper fan, have been for 17 years.

Since many in the forum tend to like the idea of open standards, perhaps JPEG2000 would be a good image support option unless you can get better lossless compression with faster display, but I am impressed with Manifold 9 and how fast it works... the internal storage format for imagery is far faster than that esri, but that's a low bar.

adamw


7,903 post(s)
#11-May-18 16:25

In the case of GPKG, that's not for us to decide - there is a standard which says which formats are allowed and neither HEIF nor JPEG2000 are on the list, unfortunately.

We do support standalone JPEG2000, but not HEIF. We will support HEIF if there is demand, no problem.

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