Which image filter to use

Hello, could you indicate me some criteria (or any filter) that allow me to say that image 1 has a bigger brighter region than any bright region in image 2?

thanks in advance.

img1

img2

[yanqi liu]

yes，sir，may be use adaptive_mediafilter、imadjust and so on to enhance target area

[Jórdan Venâncio Leite]

thanks for your answer yanqi liu i'll try it

Answer 1

[Image Analyst]

There is no hope of identifying regions that have any relation to the actual physical bubbles. Like I've said before you need to just concentrate on builk properties than trying to do particle sizing. For example, you can say that the mean gray level of the bottom image is greater than that of the top image.

[Jórdan Venâncio Leite]

Image Analyst, do you think that i can use variance filter (standard deviation) or histogram to achieve this ? Thanks for your answer once more.

[Image Analyst]

You can get the brightness profile like this:

verticalProfile = mean(grayImage, 2);
plot(verticalProfile, 'b-', 'LineWidth', 2);

You can then examine the vertical profile to learn where the bubbles are. A variance filter won't be any better than the original image, in fact it might be worse. A histogram doesn't have any information on where the pixels with those gray levels are.

[Jórdan Venâncio Leite]

Ok Image Analyst, i'll analise it txs for your answer