This article focuses on how to improve the performance of Imatest IT testing using configuration (ini file) settings.
Limiting the number of regions used to test, limiting the size of the regions
API Section Settings
Disable messages and figures
[api]
nomsg = 1
disable_figs = 1
Settings for Slanted-Edge modules: SFR, SFRplus, eSFR ISO, Checkerboard, SFRreg
Many of the settings described here are also listed in Using Rescharts slanted-edge modules Part 2: Speeding up runs. (Although Imatest IT does not run Rescharts directly, Rescharts is used in Imatest Master to make and save settings that can be used in several fixed modules as well as Imatest IT.)
Enable the “speedup” setting, this disables noise & histogram calculations which are probably not necessary for manufacturing tests. Will achieve about a 6% speed increase.
speedup = 1
Enable Luminance (Y) channel-only (single color channel) calculation. This skips the MTF calculations for the RGB channels. [RGBY_value from 1 to 4 calculates all four RGBY channels, emphasizing R, G, B, or Y, respectively). RGBY_value from 5-8 calculates one individual R, G, B, or Y channel.]
RGBY_value = 8
Disable Edge roughness calculations.
edgerough = Min
Disable the Acutance (formerly SQF) calculation if not needed.
anlz_sqf = 0
Turn off outputs you don’t need, keep JSON outputs which are the most useful
saveCSV = 0
saveXML = 0
saveJSON = 1
Beyond INI file settings these are additional ways of speeding up:
If your processor has efficency cores, it might be trying to run Imatest on them to save power. Deploy the CoreDirector utility to force Imatest to only run on performance cores.
Run multiple tests in parallel using Imatest IT Parallel
decrease the number of selected SFR regions to a minimum
disable other calculation settings that are not necessary
Use the DLL version of Imatest IT instead of the EXE
Use direct passing of image data in an array instead of a file on disk
Larger cache memory is better
Imatest libraries take a bit of time to initialize, so make sure to only initialize them once per process cycle
Throw hardware at the problem. Imatest loves to have lots of CPU cores to calculate its Fourier transforms, our 6-core LGA-2011 i7 processors are screaming fast. The more cores the merrier, although hyperthreading doesn’t help too much. Clock speed is also your friend.