What's the difference between cvtype values in OPENCV?

Question

I tried a lot of constant values but I cannot find any difference between cvtype values. What is it used for? I tried values like CV_8UC4 and CV_16S. I did not find this information in references.

Answer 1

The naming sheme for the types is CV_<bit-depth>{U|S|F}C<number_of_channels>.

So CV_8UC4 translates to: four channels of unsigned char and CV_16S translates to: 1 channel of signed 2-byte integer.

Of course the topic is handled in the documentation. Here you can find more information.

Answer 2

CV_8U - 8-bit unsigned integers ( 0..255 )

CV_8S - 8-bit signed integers ( -128..127 )

CV_16U - 16-bit unsigned integers ( 0..65535 )

CV_16S - 16-bit signed integers ( -32768..32767 )

CV_32S - 32-bit signed integers ( -2147483648..2147483647 )

CV_32F - 32-bit floating-point numbers ( -FLT_MAX..FLT_MAX, INF, NAN )

CV_64F - 64-bit floating-point numbers ( -DBL_MAX..DBL_MAX, INF, NAN )

---

8-bit unsigned integer (uchar)

8-bit signed integer (schar)

16-bit unsigned integer (ushort)

16-bit signed integer (short)

32-bit signed integer (int)

32-bit floating-point number (float)

64-bit floating-point number (double)

enum { CV_8U=0, CV_8S=1, CV_16U=2, CV_16S=3, CV_32S=4, CV_32F=5, CV_64F=6 };