[Solved] How to create gray scale QImage(QImage::Format_Indexed) without copying memory

[joonhwan]

I'm trying to create QImage that wrap a existing image buffer that is created by OpenCv I was considering use following constructor to do this.

@QImage::QImage ( const uchar * data, int width, int height,
int bytesPerLine, Format format )@

so, my code is like

@
QImage qimage((const uchar*)iplImage->imageData,
iplImage->width, iplImage->height,
iplImage->widthStep,
QImage::Format_Indexed); // qimage's buffer is now just pointing the 'iplImage->imageData'
// without allocating and copying buffer.
qimage.setColorTable(grayScaleColorTable); // color table's item count 256 for grayscale.
// now new image buffer is allocated and copied from original here.
@

Ok, no memory copy actually was done at the time of calling this ctor. But, here comes my problem. QImage::setColorTables() is non const member function where QImage allocates new image buffer for copying by its internal detach() function.

I found there was Qt3 support for this kind of problem where ctor could accept color table as argument in its ctor, but I've not found any such support in > Qt4.

How can I create gray scale QImage for existing image buffer?

Thanks for in advance

[joonhwan]

I got feedback from "SO post":http://stackoverflow.com/questions/13597058/how-to-create-gray-scale-qimageqimageformat-indexed-without-copying-memory

I should have used

@
QImage ( uchar * data, int width, int height, Format format )
QImage ( uchar * data, int width, int height, int bytesPerLine, Format format )
@

instead of

@
QImage ( const uchar * data, int width, int height, Format format )
QImage ( const uchar * data, int width, int height, int bytesPerLine, Format format )
@

[Rahul Das]

Nice..