1 | IntegralImage with ~2 bytes per pixel |
2 | (instead of 4) |
3 | |
4 | -- doesn't work... probably need column and row high bytes instead. complicated |
5 | |
6 | It can almost be done (the actual feasible byte count is 3.03125) |
7 | |
8 | Image itself: 2 bytes per pixel (just cut off and interpret as signed integer) |
9 | |
10 | Helper structure: For every 8*8 block, |
11 | store the missing highest byte |
12 | of pixel in top-left corner |
13 | |
14 | (Explanation: In an 8*8 block, the pixel sum |
15 | is at most 8*8*255=16320 which is < the signed int range.) |
16 | |
17 | So additional bytes needed per pixel: |
18 | 1/64 (for small images) |
19 | 1/32 (for big images) |
20 | |
21 | => Total bytes per pixel: |
22 | between 2.01562 and 2.03125 |
23 | |
24 | Cost for a pixel lookup: |
25 | three fixed shifts, an AND, an array lookup and an addition |
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| Snippet ID: | #1032247 |
| Snippet name: | IntegralImage with ~3#2 bytes per pixel (instead of 4) |
| Eternal ID of this version: | #1032247/7 |
| Text MD5: | f458910725a357f3d177f28ceb4fdcde |
| Author: | stefan |
| Category: | javax / imaging |
| Type: | Document |
| Public (visible to everyone): | Yes |
| Archived (hidden from active list): | No |
| Created/modified: | 2021-08-23 03:22:27 |
| Source code size: | 768 bytes / 25 lines |
| Pitched / IR pitched: | No / No |
| Views / Downloads: | 133 / 60 |
| Version history: | 6 change(s) |
| Referenced in: | [show references] |