Qtプログラミングの変換8,16 bitの階調図

コードは大体次のようなものです.8 bitの階調図で、16 bitではありません.
 

 1 QString img_path = "C:\\Users\\Yajun Dou\\Desktop\\test.bmp";

 2 QImage buff(img_path);

 3 QImage image; 

 4 uchar* pImageData1 = NULL,*pImageData2 = NULL;

 5 

 6 pImageData1 = buff.bits();

 7 

 8 image = buff.convertToFormat(QImage::Format_Indexed8);

 9 

10 QVector<QRgb> table(256);

11 for( int i = 0; i < 256; ++i )

12 {

13 table[i] = qRgb(i,i,i);

14 }

15 

16 image.setColorTable(table);

17 

18 for(int i =0; i< image.width();i++)    

19 {

20 for(int j=0; j< image.height();j++)

21 {

22 QRgb pix_value = image.pixel(i,j);

23 image.setPixel(i,j,qGray(pix_value));

24 }

25 

26 }

27 

28 pImageData2 = image.bits();

29 image.save("D:\\out.bmp",0,100);

30 

31  

 
references:
http://qt-project.org/faq/answer/how_can_i_convert_a_colored_qpixmap_into_a_grayscaled_qpixmap
http://www.qtcentre.org/threads/46596-How-to-convert-a-32-bit-RGB-image-to-8-bit-gray-scale-image
http://www.qtcentre.org/threads/19296-is-there-a-simple-and-quick-way-to-convert-color-images-to-gray-image
http://www.qtcentre.org/threads/15186-QImage-Greyscale-8-bits-pixel
http://stackoverflow.com/questions/15672743/convert-16-bit-grayscale-to-qimage