Epic for a few connected issues on image loading optimisation. Goal is to roughly double initial image loading speed of FITS images for version 3.0-beta.3 (and have performance gains for HDF5 files when contouring).
As a comparative benchmark: DS9 can load a 64K x 64K FITS image on my machine in 10 500 ms (time from clicking "Load" to the image being displayed). The same thing in CARTA takes 17 500 ms. 1700 ms of that time is taken up by the histogram calculation, and 500 ms is taken up by downsampling and compressing tiles, so there's still a lot of room for improvement. Simply reading the same image into memory using fits_read_pix takes 7500 ms, so we should be able to get our loading time down to ~ 10 seconds.
Epic for a few connected issues on image loading optimisation. Goal is to roughly double initial image loading speed of FITS images for version 3.0-beta.3 (and have performance gains for HDF5 files when contouring).
As a comparative benchmark: DS9 can load a 64K x 64K FITS image on my machine in 10 500 ms (time from clicking "Load" to the image being displayed). The same thing in CARTA takes 17 500 ms. 1700 ms of that time is taken up by the histogram calculation, and 500 ms is taken up by downsampling and compressing tiles, so there's still a lot of room for improvement. Simply reading the same image into memory using
fits_read_pix
takes 7500 ms, so we should be able to get our loading time down to ~ 10 seconds.