[SOLVED] display greyscale image with label and QPixmap

jk_mk

Hi, I am using QPixmap and Qlabel in order to display a greyscale image. I am using QImage::Format_RGB32 and I get my image with blue color. But I have noticed that the other format supported by QImage, do not give me the right results for the greyscale image.Could somebody give me an advice in this problem? How I could display a greyscale image using the following code?

@ QImage *image_Qt = new QImage (size_x,size_y,QImage::Format_RGB32);

InputImageType::Pointer image = reader->GetOutput();

for(unsigned int i = 0; i < size_x-1; i++)
  {
  for(unsigned int j = 0; j < size_y-1; j++)
  {
    InputImageType::IndexType pixelIndex;
    pixelIndex[0] = i;
    pixelIndex[1] = j;

   unsigned int value= image->GetPixel(pixelIndex);
   image_Qt->setPixel(i,j, value );
  }

  }

destroyed(ui->label_6);
QPixmap *map=new QPixmap ;
map->fromImage(*image_Qt);
ui->label_6->setPixmap(QPixmap::fromImage(*image_Qt));@

dangelog

What does
@
unsigned int value= image->GetPixel(pixelIndex);
@
do?

jk_mk

I should have mention this.They are some methods of a library named ITK, for medical image processing.To be more spesific this unsigned int value= image->GetPixel(pixelIndex);, gives the value of a pixel of the image which has index (i,j).For greyscale images has range [0,255]

mlong

Can you clarify your problem? Is it that you're sampling a greyscale 8-bit image, and when you're trying to show it in a RGB32 Image, you're only getting shades of blue? If so, that's because you're effectively using a RGB value of 0xff0000bb, where bb is the value read from your greyscale image [0,255].

jk_mk

Yes this is my problem, I get my image but with a blue shade over it.What format should I use?Or what change should be done?

mlong

You need to account for the red and green channels in the QRgb value.

See "here":http://doc.trolltech.com/4.7/qimage.html#pixel-manipulation for some hints.

jk_mk

Thanks a lot this has solved my problem