Many image formats support tiling so you don’t need to have the entire image in memory (since a very large image is usually scaled or only a portion used at a time).
> On Jan 24, 2022, at 10:07 AM, Howard C. Shaw III <howardcs...@gmail.com> > wrote: > > > One more options to add to Tamás' suggestions - due to Go's interface > design, implementing a draw.Image, which is an image.Image with an additional > Set(x, y int, c color.Color) method, is sufficient to use draw.Draw for > compositing. > > As such, you can pre-allocate a flat-file with sufficient space to store 4 x > 8 x width x height bytes > (4 for RGBA, 8 for float64 in bytes), and have your implementation of > draw.Image reading and writing > to the file by offset. This would minimize memory usage in exchange for a > massive slowdown, as > every *pixel* operation would now be a read or write to a file, but only one > of the small files needs to be open > at a time. MMapping this file can get some of the performance back, as Tamás > suggested, or you can have the file be on a RAMdisk - this alleviates less of > the performance issue, as it still requires filesystem operations per-pixel, > but is not as slow as dealing with actual spinning media. > > You would still at some point need to pull in the entire large file to write > it into a usable format, so whether there is any significant advantage > depends on whether your large file has an area equal to or larger than the > sum of the areas of the individual images - that is, to what degree the > images are being composited with overlap. > > > > -- > You received this message because you are subscribed to the Google Groups > "golang-nuts" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to golang-nuts+unsubscr...@googlegroups.com. > To view this discussion on the web visit > https://groups.google.com/d/msgid/golang-nuts/2710cbd7-ed44-4343-830b-1b661d0b70d7n%40googlegroups.com. -- You received this message because you are subscribed to the Google Groups "golang-nuts" group. To unsubscribe from this group and stop receiving emails from it, send an email to golang-nuts+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/golang-nuts/C07F4399-2169-4A4B-9856-1D1BCCE926B7%40ix.netcom.com.
