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What, if any, would be the main benefit of using a commercial tool like eCognition (in particular) or ERDAS as opposed to something like Orfeo Toolbox or OpenCV? (Feel free to suggest other open source software for RS if you think it fills a gap also.)

Put aside the GUI as I would likely be scripting it anyway. It seems to me that most of the fundamentals of Remote Sensing are available as easily scriptable OSS elsewhere.

Things like mosaicing, edge detection, basic band calcs e.g. (Band_1 - Band_2) that can be strung together for things like NDVI, supervised and unsupervised classification, high/low pass filters etc all seem to be available. Furthermore the basic C++ programs written for these are no more complicated than Python given the level at which the methods are exposed to the user.

I am assuming the commercialproducts shine when it comes to more advanced stuff like object recognition and the like. Also I assume they would have the benefit of a helpdesk or support if required.

I have used the free trial for eCognition but given that I am usually doing pretty basic stuff I never get a chance to see where it may be better. I am also assuming that it takes a while cutting your teeth on the basics in a program to realise the helpful time savers and get the most benefit out it. Time you don't really get when using a trial version.

Is there anything I am missing? Anything that completely stands out that you are thinking 'Wow! this guy is an idiot for not knowing about capability X'? Conversely do you think it is true that most of this stuff is basic technology that has been around for years so it is only the more advanced part of the market pushing the technological envlope that requires these tools?

closed as primarily opinion-based by PolyGeo Nov 11 '16 at 22:53

Many good questions generate some degree of opinion based on expert experience, but answers to this question will tend to be almost entirely based on opinions, rather than facts, references, or specific expertise. If this question can be reworded to fit the rules in the help center, please edit the question.

  • open source is a very name to use it would be better to know what you want to compare? also you mentioned too many concepts, stick to one such as i want to do NDVI or i want to object recognition. – Abhijit Gujar Oct 20 '15 at 13:36
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My recommendation is that you focus on the functionality of the software and use the package you need to get the job done. Don't assume that commercial products have better support as the open source community is wonderful. In the case of eCognition it can do things related to object-based image analysis that, quite frankly, no other software package can touch. If you want to get into eCognition check out the eCognition User Community, as it is one of the best out there. What I like about it is that the eCognition staff and lots of end users share their rule sets. On my blog I have a lot of eCognition tips and video tutorials. http://letters-sal.blogspot.com/search/label/eCognition

  • I think you're right. In the short term I will see what I can get done for free. Then as my requirements change I will review the software I am using. Looks like it is open now but I seem to remember the eCognition Community bing restricted to customers previously. At present just trying to get RS as a day to day work item rather than having it outsourced. Very cool blog/site btw. – EnE_ Aug 29 '12 at 0:12
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From own experience, I can warmly recommend having a look at GRASS GIS 7. It can handle a huge amount of data and comes with a lot of RS tools out of the box (from image enhancement, via segmentation to classification, see: grass.osgeo.org/grass72/manuals/imageryintro.html). This functionality can be extended by a bunch of AddOns (grass.osgeo.org/grass70/manuals/addons/).

GRASS is perfect for scripting and fully integrates GIS and RS.

A particular strength is handling of time series (grass.osgeo.org/grass72/manuals/temporalintro.html) which becomes especially useful for space-borne RS data from satellites with a high revisit frequency.

I suggest having a look at the following videos for a general intro:
de.slideshare.net/markusN/neteler2014-foss4g-grass7talk-38994832
(video at vimeo unfortunately removed)

for handling Sentinel-data:
av.tib.eu/media/20425?141

for object-based image analysis:
av.tib.eu/media/20409?76

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