May 8, 2011 at 7:06 pm #1865chupathingieParticipant
soosh posted some macro shots using Zerene Stacker and that got me wondering about what open-source software was available to do the same.
So I started playing around with Enfuse, since it has an option to fuse based on contrast. It works, and it’s fairly fast, but leaves rather obvious halos around any high-contrast areas that border across different depths of field.
I got sidetracked using Enfuse to composite based on exposure (as an HDR technique) for a couple days but got back on track yesterday with the focus stacking by downloading ImageJ and a couple of plugins for depth of field compositing.
I like IMageJ so far, I’ve used the Extended Depth of Field and the Stack Focuser plugins.
I took a stack of 25 images that I focused at small increments as a test run with a 5DmkII so I could see if it could handle large image files. I started with the Extended Depth of Field plugin and ran it through using the “quick” settings. Very obvious halos, but I thought maybe the “quality” setting would look better. I let that run for over 12 hours before I decided that the plugin is just not suited for large images. It’s just too slow, but it might work well for fewer images in the stack.
Next I downloaded the Stack Focuser plugin and ran my images through it. I like this one much better, the halos are much less obvious and even when I bumped the sample size way up (I doubled the default setting from 11X11 pixels to 22X22) it still managed to combine the stack in under 10 minutes.
It’s unaltered from the ImageJ output, and I did need to run the originals through align_image_stack before adding them into a stack in ImageJ. The FOV changes while changing focus will of course need to be cropped out, but I was expecting that.
Oh, and a heads-up to anyone that wants to try this… ImageJ runs with a default of 512meg allocated to the java engine (it’s java-based). If you are running large images or a large number of images through it, you might want to open that up a bit. I reset the default to use 12000meg, and wound up using almost all of that on this stack; and that was with 8-bit images. Plan accordingly if you’re going to run 16-bit through this (it will handle 16-bit, and face it… you’re going to do them that way anyway, aren’t you?).
Anyone have any focus-bracketed macro shots they wanna share for science? I’d like to see if there’s any difference in the halos between some macro subs vs my dining table setup. I tried to use high-contrast items as a stress test, so I’m expecting better results with anything that might have less dynamic range.
I’m really looking forward to some goodies from B&H now…
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