# Roughness test on for painting on the wall

Tags: #<Tag:0x00007fb87e436f00>

#1

good evening everyone!

I need a way to determine how rough are the walls after painted with paint. Can anyone help me figure out a way to calculate how rough is the surface?

thanks for helping!

I have tried using this plugin: https://imagej.nih.gov/ij/plugins/waveness-roughness.html
but this plugin seems to have some issue
and I also tried this plugin: https://imagej.nih.gov/ij/plugins/roughness.html
but it gives very similar result

any ideas, advice or method will be greatly appreciated!
thanks a lot for your help!
regards
mcenroe ng

#2

Good day,

please realize that what you want is information about the third dimension which isn’t as such accessible from images. That said, you need indirect cues and that’s where the problem starts …

An analysis of your images can tell us something about 2D-evenness/regularity and about the texture but the roughness, i.e. the elevation of the paint from the base plane, can only be estimated from the shadows and these depend on the illumination of the wall.

If you are interested in the differences of the images, regardless where the come from, I recommend using Fourier-spectral or auto-correlation measures.

Regards

Herbie

#3

hello Herbie!

Information about irregularity will be good too! i need to extract as much information as possible from image J. cause I have to amalyse the sample which i i am having a very tough time. thanks for your help !

so any plugin you can recommend will be good!

regards
mcenroe ng

#4

Good day,

you may have a look at a related question and Forum-thread:
http://forum.imagej.net/t/how-to-analyze-regularity-of-an-image/9195/7?u=herbie

Regards

Herbie

#5

is there any way that i can use image J to obtain exactly like the shown presentation?

#6

@Herbie you know how? thank you!

#7

These steps might help. I wasn’t sure if your after the Standard Deviation or the Mean Absolute Deviation so both are there.

1. Process > Subtract background... Select Rolling Ball of radius 20 (large enough to average over the roughness scale)

2. This creates the second image. I’ve plotted line profiles to show the image intensity is flattened.

3. Analyse > Set Measurements..., make sure Standard deviation and ```Mean grey value`` are s selected.

4. Analyse > Measure. Standard deviation is in the results table, square this to get R_alpha (if there was a squared there).

5. Otherwise copy the Mean from the Results table,

6. Process > Math > Macro... and enter this formula v=abs(v-227.551) (paste the Mean here). This makes an image of absolute deviations.

7. ``Measure``` the new image. The Mean on in the Results Table is the Mean Absolute Deviation.

#9

do you know how to get this data?

thank you very much

regards
mcenroe ng

#10