| y4mscaler | yuvscaler | |||
| M/N | box | cubic | RESAMPLE | BICUBIC |
| 2/3 |  |
 |
 |
 |
| 1/2 |  |
 |
 |
 |
| 1/3 |  |
 |
 |
 |
| 1/4 |  |
 |
 |
 |
yuvscaler is the video scaler which ships with MJPEGtools.
yuvscaler implements two scaling modes, "RESAMPLE" and "BICUBIC". The following table compares their step responses in downsampling, compared to y4mscaler's box and cubic kernels.
yuvscaler is invoked as follows for the test:
yuvscaler -v 0 -M RESAMPLE -M RATIO_M_N_1_1 -O SIZE_120x120
yuvscaler -v 0 -M BICUBIC -M RATIO_M_N_1_1 -O SIZE_120x120
| y4mscaler | yuvscaler | |||
| M/N | box | cubic | RESAMPLE | BICUBIC |
| 2/3 | |
|
|
|
| 1/2 | |
|
|
|
| 1/3 | |
|
|
|
| 1/4 | |
|
|
|
From this comparison, it is apparent that yuvscaler's RESAMPLE mode is equivalent to a box filter. And the BICUBIC mode has some odd asymmetries.
|
maximum impact research Digital Media Group <dmg at mir.com> |
Last modified: Sun Dec 11 14:55:47 EST 2005 |
©2003 Matthew Marjanovic.
This material may not be republished in any form
without express written consent of the author.