Hi,
On Tue, Apr 29, 2014 at 9:17 AM, OTB Florian <[email protected]> wrote: > Hi, > > 337300 and 7674920 are just the coordinates of the image origin I got with > otbcli_ReadImageInfo command or by adding the line > std::cout << cloudDetection->GetInput()->GetOrigin() << std::endl; > in the code. > This is wrong. You are confused with image pixels and image coordinates here. What you are talking about is the projected coordinates of image. Image pixels starts with 0,0 is most image processing software. IIRC, Matlab is an exception in this case. But anyway here if you are trying to get the pixel for the entire image, the best thing is to use image iterators which gives you efficient access to pixels. If you want to get a single pixel as you mentioned in your case. The image pixels starts with 0,0 and end with (width-1, height-1) pixelIndex[0] = 0 pixelIndex[1] = 0 And for another case if you want to get a pixel at a particular coordinates say you only know lat,lon -> You need to find the corresponding pixel location based on the projection and use it. > > Le lundi 28 avril 2014 17:09:08 UTC+1, Rashad a écrit : >> >> Hi, >> >> >> On Mon, Apr 28, 2014 at 10:49 AM, OTB Florian <[email protected]> wrote: >> >>> Hi Rashad, >>> >>> Thanks for your reply. >>> I've tested all the examples you recommanded to me. >>> >>> I'm still working on the cloud detection example and always >>> experimenting the same problem. >>> I've just added theses code lines after cloudDetection->SetInput(reader >>> ->GetOutput()); (l.157 : https://github.com/echristophe/OTB/blob/master/ >>> Examples/FeatureExtraction/CloudDetectionExample.cxx) : >>> >>> OutputImageType::IndexType pixelIndex; >>> pixelIndex[0] = 337300; >>> pixelIndex[1] = 7674920; >>> unsigned short int pixelValue; >>> for (int i = 0; i < 4; i++) { // cause it's a 4-band image >>> pixelValue = cloudDetection->GetInput()->GetPixel(pixelIndex)[i]; >>> std::cout << "GetPixel[" << i << "] = " << pixelValue << std::endl; >>> } >>> >>> >>> Then I get senseless values which are different at each execution. >>> >>> >> >> How do you find the pixelIndex in the code? >> >> pixelIndex[0] = 337300; >> pixelIndex[1] = 7674920; >> >> Could you please elaborate the calculation of "337300" and "7674920" ? >> >> >>> Any idea? >>> >>> Thanks in advance. >>> >>> >>> Le vendredi 25 avril 2014 11:11:08 UTC+1, Rashad a écrit : >>>> >>>> Hi OTB, >>>> >>>> >>>> On Fri, Apr 25, 2014 at 11:50 AM, OTB Florian <[email protected]>wrote: >>>> >>>>> >>>>> Hi all! >>>>> >>>>> I'm new at OTB and studying some examples to become familiar with the >>>>> library. >>>>> >>>>> >>>> You might start with the first example - http://www.orfeo-toolbox.org/S >>>> oftwareGuide/SoftwareGuidech4.html >>>> >>>> >>>>> I've tried the cloud detection example (https://github.com/echristoph >>>>> e/OTB/blob/master/Examples/FeatureExtraction/CloudDetectionExample.cxx) >>>>> with the CloudsOnReunion.tif file and it works very well. >>>>> However, I'm facing some difficulties while trying to get the values >>>>> of the different (4) bands of a pixel via the GetPixel() method. >>>>> >>>> >>>> Could you post some of your code which you tried?. >>>> >>>> >>>>> I'm wondering the type returned by this method. In that case, I get an >>>>> array with four values which don't mean anything (NaN or values around >>>>> 1e-154). >>>>> Behind this trouble is the way of encoding the band intensities. Is >>>>> there any function to know the type of encoding, the min and max of each >>>>> band? >>>>> >>>> >>>> I think you must try the examples first. Sources are available here - >>>> http://hg.orfeo-toolbox.org/OTB/file/fc0c18977f12/Examples/Tutorials >>>> >>>> [1] http://www.orfeo-toolbox.org/SoftwareGuide/SoftwareGuidech4.html >>>> >>>>> >>>>> >>>> >>>>> If you could help me... >>>>> >>>>> Thanks. >>>>> >>>>> -- >>>>> -- >>>>> 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 the Google >>>>> Groups "otb-users" group. >>>>> To unsubscribe from this group and stop receiving emails from it, send >>>>> an email to [email protected]. >>>>> >>>>> For more options, visit https://groups.google.com/d/optout. >>>>> >>>> >>>> >>>> >>>> -- >>>> Regards, >>>> Rashad >>>> >>> -- >>> -- >>> 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 the Google >>> Groups "otb-users" group. >>> To unsubscribe from this group and stop receiving emails from it, send >>> an email to [email protected]. >>> For more options, visit https://groups.google.com/d/optout. >>> >> >> >> >> -- >> Regards, >> Rashad >> > -- > -- > 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 the Google Groups > "otb-users" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > For more options, visit https://groups.google.com/d/optout. > -- Regards, Rashad -- -- 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 the Google Groups "otb-users" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
