Thanks! For the first task I think you probably have to use the raw bitmap% object (since I guess you're using `read-bitmap`). I'm not sure if there could be some improvement internally so that screen bitmaps were used to read in the jpegs. Absent an improvement at that level, I guess I'd just try caching the conversions.
For the second, I guess you are creating very small bitmaps so probably this particular creation issue isn't affecting that part? If you really have a lot of them, you could probably implement some clever pooling that wasn't keeping all of the jpegs in actual bitmap% objects all the time but was just keeping ones that were likely to be looked at soon in bitmap% objects. hth, Robby On Thu, Apr 23, 2020 at 10:05 AM 'racket' via users-redirect <us...@plt-scheme.org> wrote: > > Hi Robby, thanks for your reply. > > > What are you using the bitmap for, exactly? Just to resize the bitmaps? Or as > a backing store for drawing into the canvas? Something else? > > Both of them. > > * I have more than 10K photos in 4000x3000 format that I’d like to download > from a webdav server, read exif info, and resize to 960x720 and 320x240 > > * I should display the thumbnails in a canvas, keeping the system as smooth > as possible while scrolling the canvas. > > For the first task, if I don’t find any valid alternative, I could use some > external tool to resize the images (let’s say libvips or imagemagick) or > maybe write some ffi code to use libjpeg. I would prefer this solution over > the first one, but I don’t have any experience with ffi coding. > > > Thanks, > > Andrea > > -- > You received this message because you are subscribed to the Google Groups > "Racket Users" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to racket-users+unsubscr...@googlegroups.com. > To view this discussion on the web visit > https://groups.google.com/d/msgid/racket-users/etPan.5ea1ae9c.ee2bf71.17869%40andreagiardina.com. -- You received this message because you are subscribed to the Google Groups "Racket Users" group. To unsubscribe from this group and stop receiving emails from it, send an email to racket-users+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/racket-users/CAL3TdONHF8qPj35yw0wBjLcHk4eiJL8%3Dmdde%3DcQNBKiB6_0xHg%40mail.gmail.com.
