How to get/(convert to) BGR images through nvxio?

Autonomous Machines Jetson & Embedded Systems Jetson TX1
#1

Hi, recently our algorithms mainly use bgr raw image format. But I found VX_DF_IMAGE only supports:

VX_DF_IMAGE_VIRT
A virtual image of no defined type.
VX_DF_IMAGE_RGB
A single plane of 24-bit pixel as 3 interleaved 8-bit units of R then G then B data. This uses the BT709 full range by default.
VX_DF_IMAGE_RGBX
A single plane of 32-bit pixel as 4 interleaved 8-bit units of R then G then B data, then a don’t care byte. This uses the BT709 full range by default.
VX_DF_IMAGE_NV12
A 2-plane YUV format of Luma (Y) and interleaved UV data at 4:2:0 sampling. This uses the BT709 full range by default.
VX_DF_IMAGE_NV21
A 2-plane YUV format of Luma (Y) and interleaved VU data at 4:2:0 sampling. This uses the BT709 full range by default.
VX_DF_IMAGE_UYVY
A single plane of 32-bit macro pixel of U0, Y0, V0, Y1 bytes. This uses the BT709 full range by default.
VX_DF_IMAGE_YUYV
A single plane of 32-bit macro pixel of Y0, U0, Y1, V0 bytes. This uses the BT709 full range by default.
VX_DF_IMAGE_IYUV
A 3 plane of 8-bit 4:2:0 sampled Y, U, V planes. This uses the BT709 full range by default.
VX_DF_IMAGE_YUV4
A 3 plane of 8 bit 4:4:4 sampled Y, U, V planes. This uses the BT709 full range by default.
VX_DF_IMAGE_U8
A single plane of unsigned 8-bit data. The range of data is not specified, as it may be extracted from a YUV or generated.
VX_DF_IMAGE_U16
A single plane of unsigned 16-bit data. The range of data is not specified, as it may be extracted from a YUV or generated.
VX_DF_IMAGE_S16
A single plane of signed 16-bit data. The range of data is not specified, as it may be extracted from a YUV or generated.
VX_DF_IMAGE_U32
A single plane of unsigned 32-bit data. The range of data is not specified, as it may be extracted from a YUV or generated.
VX_DF_IMAGE_S32
A single plane of unsigned 32-bit data. The range of data is not specified, as it may be extracted from a YUV or generated.

how can I convert vx_images from RGB to BGR format?

Thanks!

#2

If you don’t want to use opencv converter, you can try to extract channel first, and then combine them with preferred order.

For example:

vxChannelExtractNode(graph, inputRGB, VX_CHANNEL_R, channelR)
vxChannelExtractNode(graph, inputRGB, VX_CHANNEL_G, channelG)
vxChannelExtractNode(graph, inputRGB, VX_CHANNEL_B, channelB)
vxChannelCombineNode(graph, channelB, channelG, channelR, NULL, outputBGR)

Following tutorial also use channel extract and channel combine. You can take a look.
https://www.brainshark.com/nvidia/vwb-simplecv

#3

Thanks AastaLLL!

#4

Hi AastaLLL,

How can I convert VX_DF_IMAGE_S16 to VX_DF_IMAGE_U8?

Thanks

#5

Hi,

Please check the convert bit depth node.
You can find more information of VisionWorks document:

VisionWorks API
Khronos OpenVX 1.1 API
OpenVX API Modules
Vision Functions
Convert Bit Depth

Thanks.

#6