SageThumbs 2k Files

What's changed

Changed

• Game textures with mipmaps thumbnail about 17x faster. A .dds file usually already contains the picture at every halved size down to 1 pixel, because that is what a game engine displays at a distance. We were ignoring all of it and decompressing the full-size image to build a small tile. An 8192 x 8192 texture went from 0.87 seconds to 0.05. The tile now comes from the texture's own smaller copy, so it looks very slightly softer than a full decode would, which is exactly what the game itself shows.

Fixed

• "Image info" reported the wrong size for large JPEG 2000 files. A 9958 x 7686 map scan confidently described itself as 4096 x 3161. Nothing could read a .jp2 header directly, so the size was taken from a full decode, and that decode is capped at 4096 pixels for safety. The number you were shown was the cap, not the picture. It now reads the real dimensions straight out of the file in about a third of a second, without decoding anything.

• Very large images thumbnailed about twice as fast, and huge scans stopped timing out. A 76-megapixel JPEG 2000 map scan (only 11 MB on disk) took around 9 seconds and, on a busy folder, missed the preview pane's time limit entirely, so the pane showed nothing for a file that was perfectly readable. The problem was not the file's size: whatever you were going to see it at, the decode always rendered a 4096-pixel version first and threw most of it away. It now decodes straight to the size being displayed. That scan is about 4.4 seconds for an Explorer thumbnail and 5 seconds in the preview pane, and detail is slightly better, because the picture is no longer resized twice. Most of what remains is the JPEG 2000 decoder itself. (issue [#11])

Verified installer

• File: SageThumbs2K-Setup-1.7.4.exe
• Size: 13408770 bytes

• SHA-256: 05a16462c44521ce1da82d6aa9dd0af9f8d8b09596d80576d25fb05af0e98590

• ARM64 installer: SageThumbs2K-Setup-1.7.4-arm64.exe

• ARM64 SHA-256: 0bc9cafc417930cd388493a769eb9e3d2b957150ae9dfdfbf6c81c5d0deab211