|
![[logo]](http://repo.hu/projects/ch24retro/logo.svg){kind=logo}
|
Blog
Columns (2010/preec/R): eval
| columns_eval by Tibor 'Igor2' Palinkas on 2021-03-12 | Tags: 2010, preec, 2010preec, eval, jpeg, image, scaled |
Abstract: n/a
Datasheet
| Task | Columns |
|---|---|
| When | 2010 preec R |
| Description | html |
| Input pack | zip |
Eval
Because we had a jpeg task in the EC, we had to have one in the preec to prepare teams for loading jpeg files and processing pixels. We wanted to make a task that is easy yet fun to solve. We also wanted to make it an open ended optimization task, with a so called scaled scoring where the optimal solution is not known and your solution is compared/scaled against other teams' solutions.
Since it's preec only and the task is trivial, we did not have a solver for it, only a trivial eval for calculating the score. The eval code depends on libsdl1.2 for loading the jpeg. Before running the eval, copy all input jpeg from the problem set to input/. The eval reads the internal eval format: first line is the input file number in decimal, from 1 to 10, the second line is 0, then the submitted solution. The eval prints a raw value, the higher the better, which was then used by the eval server to compare submissions by different teams.
During the EC we figured our mistake with jpeg: various jpeg lib implementations produce raw pixels slightly differently due to color space conversion, gamma correction, etc.
The eval code is Copyright (C) 2010 Mate Nagy and is licensed under the GNU GPL version 2.