Opencv Mat Type Conversion

Qimage img uchar mat data mat cols mat rows qimage format rgb32.

Opencv mat type conversion.

To convert from cv mat to qimage you could try to use the qimage uchar data int width int height format format constructor as follows mat is a cv mat. Hi the dnn imagenet ex cpp example in line 141 load image as a matrix rgb pixel. Note that mat at int y int x and mat operator int y int x do absolutely the same and run at the same speed but the latter is certainly shorter. The second thing to notice is the switch statement in the cv mat to qimage conversion cvmattoqimage because both opencv and qt provide multiple data.

Anyone who knows how to deal with the p. The colour conversion is done by ffmpeg rather than by opencv. While mat is sufficient in most cases mat can be more convenient if you use a lot of element access operations and if you know matrix type at the compilation time. It seems that the smart pointer could work in this case.

Say i have gpumat 512 512 cv 32fc2 and i want to convert it to float2 which has 512 512 elements. The reason is i want to write my own kernel outside cv gpu modules. I want to read the image by opencv and i faced the problem to transform the type of cv mat to matrix rgb pixel. It is more efficient than manually converting the pixels to the qimage but you have to keep the original cv mat image in memory.

The first thing to note is that the cv mat to qpixmap conversion cvmattoqpixmap at the bottom of this section simply relies on cvmattoqimage and uses qt s qpixmap fromimage to return a qpixmap so that s pretty straightforward.