Particle Segmentation from mixed background

Hi all - I have these large images (this is just a snapshot) containing particles in resin. My aim is to create a binary mask to remove the background resin.

The problem I have encountered is that the resin (generally darker than the particles) contains pixels that are also in the range of those in the particles and also brighter (back lighting from microscope illumination).

So far I have tried,

• edge detection (canny, sobel) but these still pick out some of the blemishes and then constructing a mask from the mash of lines is difficult
• active contours (edge & chan-vese) but these are also unable to remove the brighter resin pixels effectively
• lazy snapping - gets confused between foreground and background

Any help/pointers would be greatly apprechiated.

Many thanks,

Joe

[KALYAN ACHARJYA]

Can you share a sample pic with pointing resin?

You have to remove resin from the images, yes?

Ofcourse, to create mask to segment no resin part.

[Joe Perkins]

Hi - there is already one attached. Called ‘mosaic’

Thanks