<html><body><div style="color:#000; background-color:#fff; font-family:HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif;font-size:10pt"><div><span>Hi David,</span></div><div style="color: rgb(0, 0, 0); font-size: 13px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; background-color: transparent; font-style: normal;"><span><br></span></div><div style="color: rgb(0, 0, 0); font-size: 13px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; background-color: transparent; font-style: normal;"><span>I couldn't find any method to input customized array in vtkImageHistogram. I'm trying to plot image projection profile. I guess I can only use vtkChartXY.</span></div><div style="color: rgb(0, 0, 0); font-size: 13px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; background-color: transparent; font-style:
normal;"><span>Thanks for the reply.</span></div><div style="color: rgb(0, 0, 0); font-size: 13px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; background-color: transparent; font-style: normal;"><span><br></span></div><div style="color: rgb(0, 0, 0); font-size: 13px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; background-color: transparent; font-style: normal;"><span>Regards,</span></div><div style="color: rgb(0, 0, 0); font-size: 13px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; background-color: transparent; font-style: normal;"><span>Harold</span></div><div class="yahoo_quoted" style="display: block;"> <br> <br> <div style="font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; font-size: 10pt;"> <div style="font-family: HelveticaNeue, 'Helvetica Neue', Helvetica,
Arial, 'Lucida Grande', sans-serif; font-size: 12pt;"> <div dir="ltr"> <font size="2" face="Arial"> On Wednesday, January 8, 2014 1:24 PM, David Gobbi <david.gobbi@gmail.com> wrote:<br> </font> </div> <div class="y_msg_container">Hi Harold,<br clear="none"><br clear="none">The vtkImageAccumulate filter doesn't draw a histogram, it computes<br clear="none">a histogram. The input of vtkImageAccumulate is an image, not an<br clear="none">array.<br clear="none"><br clear="none">It might be easier to use vtkImageHistogram. It takes an image as<br clear="none">input, and produces a histogram image as output.<br clear="none"><br clear="none"> David<br clear="none"><br clear="none"><div class="yqt2410058659" id="yqtfd15292"><br clear="none">On Tue, Jan 7, 2014 at 9:12 PM, Harold <<a shape="rect" ymailto="mailto:boogiedoll@yahoo.com" href="mailto:boogiedoll@yahoo.com">boogiedoll@yahoo.com</a>> wrote:<br clear="none">> Hi,<br
clear="none">><br clear="none">> I have a grayscale image. I want to draw a histogram where x-axis is the nth<br clear="none">> column (n = image_width -1), and y-axis is the sum of pixel value in each<br clear="none">> column. How do I pass the y-axis value (std::vector<int> ColSum; ) to the<br clear="none">> vtkImageAccumulate?<br clear="none">><br clear="none">> // Read a jpeg image<br clear="none">> vtkSmartPointer<vtkJPEGReader> reader =<br clear="none">> vtkSmartPointer<vtkJPEGReader>::New();<br clear="none">> reader->SetFileName( argv[1] );<br clear="none">> reader->Update();<br clear="none">><br clear="none">> // Convert image to image data<br clear="none">> vtkSmartPointer<vtkImageData> imageData =<br clear="none">> vtkSmartPointer<vtkImageData>::New();<br clear="none">> imageData = reader->GetOutput();<br
clear="none">><br clear="none">> // Compute the sum for each image column<br clear="none">> std::vector<int> ColSum;<br clear="none">> int image_width = imageData->GetDimensions()[0];<br clear="none">> ColSum.resize(width);<br clear="none">><br clear="none">> for(int i = 0; i < image_width; ++i)<br clear="none">> {<br clear="none">> ColSum[i] = 0;<br clear="none">> for(int j = 0; j < height; ++j)<br clear="none">> {<br clear="none">> ColSum[i] += imageData->GetScalarComponentAsDouble(i,j, 0, 0);<br clear="none">> }<br clear="none">> }<br clear="none">><br clear="none">> // Draw histogram<br clear="none">> vtkSmartPointer<vtkImageAccumulate> histogram =<br clear="none">> vtkSmartPointer<vtkImageAccumulate>::New();<br clear="none">> // ??? How to convert
"ColSum" to vtkImageAccumulate here?<br clear="none">><br clear="none">> ...<br clear="none">><br clear="none">><br clear="none">> Regards,<br clear="none">> Harold<br clear="none"></div><br><br></div> </div> </div> </div> </div></body></html>