see below for the list of nodes. Note, that you can run most of the FIJI Plugins using the ImageJ-Macro Node from the ImageJ Integration. If something doesn't work with the IJ Macro Node or you want to have a certain plugin as a dedicated KNIME node, this is actually a very easy task. Especially if the plugin is an ImageJ2 Plugin. We can automatically create KNIME Nodes from headless ImageJ2 Plugins.
- merge images with different focal length
I don't know exactly what you want to do. But we have the following nodes: Merger, Groupby, Image Calculator, etc.
- metrics for blurriness (contrast, correlation, Tamura kurtosisof directionality ?)
Image Segment Features / Segment Features: Tamura, Haralick, FirstOrderStatistics. In the next release we will have many more features.
- de-blurring (sharpen in Fiji?, CLAHE, erosion?)
ImageJ Macro Node (Sharpen, CLAHE, Rolling Ball,...), CLAHE, Morphological Operations (Erode/Dilate/Open/Close with or without Structuring Element Creator), H-Dome, Difference of Gaussian, Kernel Creator, Convolver, Image Calculator etc.
- grayscale and color calibration
What do you mean? Node like: Image Normalizer (Histogram Equalization, Saturation etc), Converter (convert between types and so on), Projector (e.g. Project Color Channels), Image Cropper, etc.
Something missing? We have a lot of nodes and especially the combination of these nodes makes the plugin so powerful. In our tutorials on: http://tech.knime.org/forum/knime-image-processing/ you find some very good examples.
Maybe one more comment: We (KNIME + ImageJ2/FIJI) are currently working on a framework called ImageJ-Ops, where we reimplement all our algorithms and merge them with the existing ones of ImageJ2 such that we have the same code-base in the near future. So everything you get in ImageJ2/FIJI you will automatically get in KNIME as a node (there are exceptions, but for most of the algorithms this statement holds).