Hi, Could you post the your full code on pastebin.com ?
On Tue, Apr 29, 2014 at 9:46 AM, OTB Florian <[email protected]> wrote: > Thanks for your explanation. > I've changed the values to 0 as you proposed but now I get a segmentation > fault when calling the GetPixel() method. > > Le mardi 29 avril 2014 08:31:07 UTC+1, Rashad a écrit : >> >> 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/SoftwareGuide/SoftwareGuidech4.html >>>>>> >>>>>> >>>>>>> I've tried the cloud detection example (https://github.com/ >>>>>>> echristophe/OTB/blob/master/Examples/FeatureExtraction/CloudDetecti >>>>>>> onExample.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. > -- 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.
