Ticket #233 (closed enhancement: fixed)
Opened 2008-01-25T14:42:25-06:00
Last modified 2008-07-18T10:39:51-05:00
Improve time performance of subimage methods
| Reported by: | melissa | Owned by: | melissa |
|---|---|---|---|
| Priority: | trivial | Milestone: | |
| Component: | bio-formats | Severity: | minor |
| Keywords: | Cc: | ||
| Blocked By: | Blocking: |
Description
The majority of openBytes(int, byte[], int, int, int, int) implementations look like this:
skip to first row of subimage
for each row in subimage {
skip to first column of subimage
read <width of subimage> bytes
skip <width of image> - <width of subimage> - <first column> bytes
}
If the subimage is nearly the same size as the full image, it may be faster to read the full image and crop as needed. We need to perform some tests to determine when cropping is faster than reading row-by-row, and improve the subimage logic as necessary.
Change History
comment:2 Changed 2008-07-18T10:39:51-05:00 by melissa
- Status changed from new to closed
- Resolution set to fixed
There doesn't appear to be an appreciable difference between reading row-by-row and reading the entire plane and cropping. Tested on 3 channel, 16 bits per channel images - 4096x4096, 1024x1024, and 512x512.