Comments by Basketcase Software (Top 2 by date)

Basketcase Software 1-Aug-18 18:11pm View

Except you forget one important detail - the OP never mentioned the usage of GDI or GDI+ - that was all you. A Canvas, a WPF construct, does not use GDI or GDI+. The OP specifically said "bitmap" and that is a VERY trivial file format to process and manipulate. Source code already exists to handle that format in just about every major programming language out there.

Your ignorance of the English language and tendency to jump to overdrawn assumptions is quite clear. I never said I was personally insulted. The only party who could have been insulted was the original poster

And insults gives the offended party typically the right of complaint to the forum administrators. Those people have the right to take measures against the party making the insults. I happen to be a board administrator elsewhere. Being snide and arrogant on a forum can come back to haunt you - you never know who you are speaking to. In my case I happen to be one of the founders of a international software company operating on four continents. That makes me an employer as well and a screener of job applicants.

Basketcase Software 22-May-17 17:44pm View

I'm finding this question, and this rather insulting answer, a bit late. I've already followed the one answer link and it dodges the question just the other posters.
Memory mapped files are for processing large files of any type efficiently without running into memory issues. If you are creating an image processing application having someone tell you to go use another image processing application to do what you are trying to do is absurd. The "break the image into smaller images" is exactly that type of answer. You assumed the person was relying on GDI or GDI+ to actually manipulate the full image.

I know my position is that I have large image that:
1) I can't resize.
2) I use another program to break into chunks. Why? Because breaking the image into chunks with a specific naming convention, etc. is precisely my goal.

Let me give the person who posted the question a valid answer even if it is a bit late.
1) Understand the format of the image file you are trying to read.
2) Create a library that will parse your memory mapped file according to that format; do not rely on GDI or GDI+ to do the decoding - they can't - you have to do your own decoding. I would create a work memory map that has a raw representation of each pixel and track the image dimensions.
3) Process your work memory map and output your results according to your needs. If you need to output a single image file of a large size for this you have to handle the encoding yourself.