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« on: May 07, 2015, 07:53:22 PM »
I have tested both pix4d and agisoft for numerous projects (aerial imaging of orchards and horticultural row crops using both modified Canon powershots and Tetracam ADC). And fuerthermore done extensive groundtruthing of NDVI maps created from mosaics. Both have their advantages and disadvantages.
In favor of Agisoft:
Price if you only need one license and will use all year round. pix4d price includes 2 licenses and also provide options for monthly rentals.
Notably better quality mosaics in terms of intensity values.
Can (after reflectance calibration) create a NDVI map from the mosaic that reflects general patterns well.
pix4dmapper produces many artefacts in the mosaic (stripes of differing intensity for example) and it is necessary to create a reflectance map from the mosaic for index calculations - another procesing step (and time!) and the output formats are not readable by standard image processing programs.
Setting up images (adding, deleting, dynamic links between screens) much more flexible.
More control over parameters of processes. With experience can get good solutions just as rapidly or even faster than pix4dmapper.
In favor of pix4dmapper:
Better job aligning chunks (even without GCPs in many cases). In both, better to avoid mutiple chunks if possible.
Better technical support. Always get a reply and followup from technical support staff. With Agisoft, seems to be a roulette whether you get any response at all.
Easier for non-technical people to use (a target market for pix4dmapper)
Provide satellite map background - often useful for project setup
Comprehensive camera database, easily updated
Can process Tetracam ADC images; although mosaics have serious quality problems due to limitations of this camera. Have not been able to successfully process any Tetracam ADC projects using Agisoft to date.
On a related note, better documentation.
We have also presented a conference paper comparing (some aspects) of the two programs; available to any interested.