As I understand it, the pattern quality is measured by the software based on the contrast (or sharpness) between the Kikuchi bands and the background. Each pattern is assigned a band contrast value, and these values are then plotted as gray levels of pixels making up a map of the scanned area; this is the band contrast map, and it is useful in getting a visual estimation of features that cause poor band contrast: grain boundaries and phase interfaces, surface imperfections - scratches, pores, small inclusions, etc. - or lattice defects such as slip bands. This also means that it is easy to get an idea on what the grain size and morphology of the analysed structure looks like, sometimes better - but also a lot more time-consuming -  than by using backscatter electron (BSE) imaging.

That being said, I assume there should be a way of extracting the actual BC values from the map using Channel 5 software.

However, I am not sure what this could be useful for. The band contrast itself is not a direct indication of the pattern indexing confidence level. The latter is given by other tools, for instance in the AZtec software (Oxford Instruments) the mean angular deviation (MAD) indicates the misfit between the measured and the calculated angles between bands, so the larger the MAD value, the higher the misfit and the lower the indexing confidence. It is also a good indicator of lattice strain or defect density.

So if you are interested in the level of indexing confidence for particular areas or points in your scanned structure for comparison purposes, I would suggest it is better to use these other indices rather than band contrast. I believe each EBSD acquisition or indexing software package provides detailed instructions in their respective manuals or help files on how these indices are calculated and what they measure.

Thanks Octav. I am gonna try to extract those datas as you mentioned. Actually i need data like indicated below. This figure belongs to (Nowell et.al)

This type of analysis investigates the effect of surface finish on the overall quality of the patterns. So for this you would need an average value for the whole scanned area, and ideally you should collect a sufficiently-large number of patterns (and from a large enough area) to be representative for the sample prep method. You may also want to collect patterns from similar areas of your sample - meaning, a similar density of grain boundaries, etc. - in order to get representative results. And you should probably compare pattern quality data (band contrast, 

Again, where you get this data from depends on the individual acquisition software you use, but it should be easily available.

Dear Semih,

as far as I understand you question, you need to extract the pattern quality or band contrast values for each pixel in your map. Since these values are automatically stored  in the data file the EBSD system creates as a result of your measurement, you can read them easily by saving your measurement as *.ctf file (in AZtec: File -> Export Channel 5 project -> format = ctf ... or rute similar to this), which creates a readable text file you can easily import into any table processor like Excel, Origin ... whatever or read in Notepad.

If you are interested only in an average value of PQ/BC parameter per whole scanned area, then you don't need to make the data export/import - you can see the averages in a summary pane in HKL Data manager (or Tango module - not sure which particular one). Similarly in EDAX/TSL OIM Analysis package.

Dear Andrej

Thank you for your contribution . I exported the pq data as a .tsv file, there are values between 0 and 255  and it worked for me. On the other hand, when I read something, I noticed a term "band slope". It also has values between 0 and 255. I am wondering that what is the difference between band slope and band contrast?