Ginny, BandMathX is available since the version 4.4.0. I suppose you are on 4.2.1.
You have to build OTB from sources if you want to use BandMathX, because I believe windows binaries of v4.4.0 are not available yet. Arnaud On Wednesday, April 29, 2015 at 8:49:41 PM UTC+2, GiNN wrote: > > Thank you for that explanation Christophe, > > Lastly, how do I go about launching the BandMathX application? > I have otb and monteverdi installed via the Osgeo4w 64 bit installer. I > only see the BandMath application. Has BandMathX been rolled out to Osgeo4W > yet? > > Cheers, > > Ginny > On Apr 29, 2015 5:13 AM, "Christophe Palmann" <[email protected] > <javascript:>> wrote: > >> >> Basically, the purpose of radiometric correction (or optical calibration) >> is to "get rid of" some parameters (like viewing angle, earth-sun >> distance, and so on) that obviously affect the values of the pixels, but >> that must not be taken into account for a change detection task for >> instance, or supervised classification... and so on. Depending on the kind >> of product to be used, radiometric correction is already performed or not; >> but it is up to the user to check this. >> >> If the answer is no, then the user have to apply this calibration, after >> having found every required parameters from the images metadata. >> >> Christophe. >> >> >> >> >> >> Le mardi 28 avril 2015 21:37:54 UTC+2, GiNN a écrit : >>> >>> Thank you Christophe, >>> >>> With your and Arnaud's explanation I grasp how pixels are handled now. I >>> will run a test an give you feedback. >>> >>> About my expression: >>> The images are WorldView2 and collected over a large period (almost two >>> years). I believe they are already calibrated. I found this equation in a >>> paper by digital globe to correct the solar geometry at the collection time >>> (d = earth-sun distance and e = sun elevation angle), so the images will >>> have more or less the same colors. So basically, a radiometric enhancement. >>> >>> Is this the same as an optical calibration? I took a look at the >>> cookbook and the formula for TOA radiance to reflectance does look similar. >>> I am new to satellite imagery and I just need the end product to be >>> appealing to the eye. (I.e. similar colors) >>> On Apr 28, 2015 10:46 AM, "Christophe Palmann" <[email protected]> >>> wrote: >>> >>>> Hi Gin and Arnaud, >>>> >>>> Sorry for the late reply. >>>> >>>> As Arnaud said in his previous message, images are handled with >>>> n-dimensional row vectors. >>>> >>>> So you can use the 'mlt' or 'dv' operators to perform multiplications >>>> (divisions) between vectors and scalars; the correct expression is simply: >>>> >>>> 1) *im1 mlt d2 dv cose* or * im1 mlt (d2/cose)* >>>> Here, im1 is similar to {pix_from_band1, pix_from_band2, >>>> pix_from_band3}. I think that the second expression is faster. >>>> >>>> 2) the expression *im1 mlt {d2} dv {cose}* is also correct, as I >>>> designed those operators to process 1d vectors as scalars (both for >>>> convenience and to make the operators more robust) >>>> >>>> 3) finally, a solution close to the one of Arnaud is *im1 mult >>>> {d2,d2,d2} div {cose,cose,cose}* >>>> Here, the operators mult and div perform element-wise multiplications >>>> (divisions) between vectors. But *im1 * {d2,d2,d2} / {cose,cose,cose}* >>>> is not correct ! (the multiplication or the division of two row vectors >>>> aren't defined, you must use mlt/dv or mult/div operators). >>>> >>>> Don't forget to define the constants 'd2' and 'cose' with the method >>>> SetConstant if you use the filter, or just provide a txt file to the field >>>> 'import context' if you use the application. You can also define 'my_e', >>>> and use cos(my_e) within the above expressions (*but don't define 'e', >>>> because this constant already exists in muparserx!*), nevertheless it >>>> is better to evaluate cose once and for all. >>>> >>>> Finally, looking at your expression, you really should consider the >>>> OpticalCalibration application, which will do the job faster than >>>> BandMathX >>>> :-) >>>> >>>> Christophe. >>>> >>>> >>>> >>>> >>>> Le jeudi 23 avril 2015 14:47:15 UTC+2, Arnaud Durand a écrit : >>>>> >>>>> Gin, >>>>> >>>>> Each pixel of your image is handled as a n-dimensional row vector, >>>>> with n the number of bands in your image. {n1, n2, n3, ...} is the syntax >>>>> of muParserX to declare row vectors that you can fill with scalars >>>>> assigned >>>>> by band. >>>>> >>>>> Hope it helps. >>>>> Arnaud >>>>> >>>>> Le jeudi 23 avril 2015 14:10:28 UTC+2, GiNN a écrit : >>>>>> >>>>>> Thank Arnaud, >>>>>> >>>>>> And yes, d and e are scalars. In fact, they are constant for the >>>>>> entire image, while the image has three bands. >>>>>> >>>>>> If I understand you correctly, this still counts as a vector >>>>>> transformation? >>>>>> On Apr 23, 2015 7:50 AM, "Arnaud Durand" < >>>>>> [email protected]> wrote: >>>>>> >>>>>>> Hi GiNN, >>>>>>> >>>>>>> I'm not sure that it is possible with such a simple expression, as >>>>>>> the doc said : >>>>>>> >>>>>>> >>>>>>> >>>>>>> *For instance, it is not possible to add vectors of different >>>>>>> dimensions (this implies the addition of a row vector with a column >>>>>>> vector),or add a scalar to a vector or a matrix, or divide two vectors, >>>>>>> and >>>>>>> so on...Thus, it is important to remember that a pixel of n components >>>>>>> is >>>>>>> always represented as a row vector.* >>>>>>> >>>>>>> However, if you know the number of bands in your image, and if d and >>>>>>> e are scalars, you might try to use vector syntax in your expression >>>>>>> like >>>>>>> that : im1*{d^2,d^2,d^2,d^2}/{cos e, cos e, cos e, cos e} >>>>>>> >>>>>>> Arnaud >>>>>>> >>>>>>> Le mercredi 22 avril 2015 21:02:15 UTC+2, GiNN a écrit : >>>>>>>> >>>>>>>> >>>>>>>> I have three-band images and I want to apply the same expression to >>>>>>>> each band and get a three-bad output. >>>>>>>> I am just starting with OTB and Monteverdi. Used installer on a 64 >>>>>>>> bit W7 machine. >>>>>>>> >>>>>>>> The expression is very simple: output_pixel = >>>>>>>> (input_pixel*d^2)/cos e >>>>>>>> >>>>>>>> I read the cookbook recipe, and concluded BandmahX is what I need. >>>>>>>> But I am not sure how to formulate the expression so that the >>>>>>>> application >>>>>>>> goes through all pixels in all three bands. >>>>>>>> >>>>>>>> Any assistance is greatly appreciated. >>>>>>>> >>>>>>>> Gin >>>>>>>> >>>>>>> -- >>>>>>> -- >>>>>>> Check the OTB FAQ at >>>>>>> http://www.orfeo-toolbox.org/FAQ.html >>>>>>> >>>>>>> You received this message because you are subscribed to the Google >>>>>>> Groups "otb-users" group. >>>>>>> To post to this group, send email to [email protected] >>>>>>> To unsubscribe from this group, send email to >>>>>>> [email protected] >>>>>>> For more options, visit this group at >>>>>>> http://groups.google.com/group/otb-users?hl=en >>>>>>> --- >>>>>>> You received this message because you are subscribed to a topic in >>>>>>> the Google Groups "otb-users" group. >>>>>>> To unsubscribe from this topic, visit >>>>>>> https://groups.google.com/d/topic/otb-users/UHugkLOJEmw/unsubscribe. >>>>>>> To unsubscribe from this group and all its topics, send an email to >>>>>>> [email protected]. >>>>>>> For more options, visit https://groups.google.com/d/optout. >>>>>>> >>>>>> -- >>>> -- >>>> Check the OTB FAQ at >>>> http://www.orfeo-toolbox.org/FAQ.html >>>> >>>> You received this message because you are subscribed to the Google >>>> Groups "otb-users" group. >>>> To post to this group, send email to [email protected] >>>> To unsubscribe from this group, send email to >>>> [email protected] >>>> For more options, visit this group at >>>> http://groups.google.com/group/otb-users?hl=en >>>> --- >>>> You received this message because you are subscribed to a topic in the >>>> Google Groups "otb-users" group. >>>> To unsubscribe from this topic, visit >>>> https://groups.google.com/d/topic/otb-users/UHugkLOJEmw/unsubscribe. >>>> To unsubscribe from this group and all its topics, send an email to >>>> [email protected]. >>>> For more options, visit https://groups.google.com/d/optout. >>>> >>> -- >> -- >> Check the OTB FAQ at >> http://www.orfeo-toolbox.org/FAQ.html >> >> You received this message because you are subscribed to the Google >> Groups "otb-users" group. >> To post to this group, send email to [email protected] >> <javascript:> >> To unsubscribe from this group, send email to >> [email protected] <javascript:> >> For more options, visit this group at >> http://groups.google.com/group/otb-users?hl=en >> --- >> You received this message because you are subscribed to a topic in the >> Google Groups "otb-users" group. >> To unsubscribe from this topic, visit >> https://groups.google.com/d/topic/otb-users/UHugkLOJEmw/unsubscribe. >> To unsubscribe from this group and all its topics, send an email to >> [email protected] <javascript:>. >> For more options, visit https://groups.google.com/d/optout. >> > -- -- Check the OTB FAQ at http://www.orfeo-toolbox.org/FAQ.html You received this message because you are subscribed to the Google Groups "otb-users" group. 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