QImage returns wrong bytesPerLine for 8-bit indexed image

Thrr

The following code returns wrong number of bytes per line, since it's an 8 bit image, isn't the width supposed to be equal to the bytesPerLine?
It does not happen with all dimensions, but only certain ones.

    int www = 311;
    int hhh = 107;
    QImage nwImg =  QImage( dt, www, hhh, QImage::Format_Indexed8 );
    const int bpl = nwImg.bytesPerLine();
    qDebug() << bpl;
    qDebug() << www;
    qDebug() << hhh;

Output

312
311
107

Christian Ehrlicher

@Thrr said in QImage returns wrong bytesPerLine for 8-bit indexed image:

isn't the width supposed to be equal to the bytesPerLine?

Where is this written in the Qt documentation?
It's aligned on a 4 (or 8, don't remember and can't find it atm) byte boundary for performance reasons. This is imo also true für e.g. native windows bitmaps.

Thrr

This post is deleted!

Thrr

I think I got it wrong, using "bytesPerLine" and "sizeInBytes" is more accurate than width() and height() when loading from raw data.