get QImage object from buffer

[Sheng]

I have databuffer which is width*height*2 byte long, every pixel is two byte long(the value is the gray scale). How can I generate a QImage object from this buffer.
It seems there is no such format in QImage.

The following image formats are available in all versions of Qt:

Constant Value Description
QImage::Format_Invalid 0 The image is invalid.
QImage::Format_Mono 1 The image is stored using 1-bit per pixel. Bytes are packed with the most significant bit (MSB) first.
QImage::Format_MonoLSB 2 The image is stored using 1-bit per pixel. Bytes are packed with the less significant bit (LSB) first.
QImage::Format_Indexed8 3 The image is stored using 8-bit indexes into a colormap.
QImage::Format_RGB32 4 The image is stored using a 32-bit RGB format (0xffRRGGBB).
QImage::Format_ARGB32 5 The image is stored using a 32-bit ARGB format (0xAARRGGBB).
QImage::Format_ARGB32_Premultiplied 6 The image is stored using a premultiplied 32-bit ARGB format (0xAARRGGBB), i.e. the red, green, and blue channels are multiplied by the alpha component divided by 255. (If RR, GG, or BB has a higher value than the alpha channel, the results are undefined.) Certain operations (such as image composition using alpha blending) are faster using premultiplied ARGB32 than with plain ARGB32.
QImage::Format_RGB16 7 The image is stored using a 16-bit RGB format (5-6-5).
QImage::Format_ARGB8565_Premultiplied 8 The image is stored using a premultiplied 24-bit ARGB format (8-5-6-5).
QImage::Format_RGB666 9 The image is stored using a 24-bit RGB format (6-6-6). The unused most significant bits is always zero.
QImage::Format_ARGB6666_Premultiplied 10 The image is stored using a premultiplied 24-bit ARGB format (6-6-6-6).
QImage::Format_RGB555 11 The image is stored using a 16-bit RGB format (5-5-5). The unused most significant bit is always zero.
QImage::Format_ARGB8555_Premultiplied 12 The image is stored using a premultiplied 24-bit ARGB format (8-5-5-5).
QImage::Format_RGB888 13 The image is stored using a 24-bit RGB format (8-8-8).
QImage::Format_RGB444 14 The image is stored using a 16-bit RGB format (4-4-4). The unused bits are always zero.
QImage::Format_ARGB4444_Premultiplied 15 The image is stored using a premultiplied 16-bit ARGB format (4-4-4-4).

[Sheng]

my code:

//change 16 bit gray scale to 8 bit gray scale
   for(int i=0;i<IMAGE_WIDTH*IMAGE_HEIGHT;i++)
           imageBuffer[i]= (*((uint16_t *)(imageBuffer+2*i)))/4;
 
//get QImage object from the buffer, this might be wrong
        QImage image(imageBuffer,IMAGE_WIDTH,IMAGE_HEIGHT,QImage::Format_Indexed8);
 
//rescale the image
        QImage smallImg=image.scaled(600,300);
 
//use QLabel object to show the image
        labelImage->setPixmap(QPixmap::fromImage(smallImg));

//change 16 bit gray scale to 8 bit gray scale
   for(int i=0;i<IMAGE_WIDTH*IMAGE_HEIGHT;i++)
           imageBuffer[i]= (*((uint16_t *)(imageBuffer+2*i)))/4;

//get QImage object from the buffer, this might be wrong
        QImage image(imageBuffer,IMAGE_WIDTH,IMAGE_HEIGHT,QImage::Format_Indexed8);

//rescale the image
        QImage smallImg=image.scaled(600,300);

//use QLabel object to show the image
        labelImage->setPixmap(QPixmap::fromImage(smallImg));

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[bhamadicharef]

You could also use a lookup table to encode you linear 16bit data
Into any of your chosen format ... SetPixmap is taking so much
Time on my embeded system at large resolution ... Any idea
How to improve this ??