Saving BayerGB8 images

[IsaacT]

Hello everyone.

I am using a GIGE camera to get color images. The camera is a HXG40 from Baumer.

The camera works almost perfectly in MAX, I get nice 8bit or 16bit (depending on pixel depth) grayscale images when i set the "Bayer Pattern" in the "Bayer Color" tab to none. 

When selecting the "GB" Bayer pattern, I get nice 32-bit color  images.

First problem : the images are always 32 bit regardless of pixel depth (12-bit per component should give a 64bit image), which means that I am loosing some data.

Second problem, when I record images using the Vision express VI, I cannot record BayerGB8 images (grayscale raws), when recording to tiff via the linked vi, I can only record 3-component  color images with 8bit per component.

Thanks a lot for your help.

[toto69]

Hi,

First of all, your camera is a mono ccd color camera, meaning that it works the same way a monochrome camera works exept there is a color filter (called a Bayer filter) in front of each pixel of the ccd sensor. The electronic is exactly the same as a mono camera. 

This mean that the color decoding is done later.

- If you select to output 8 or 16 bit grayscale, then the color decoding will be done on the PC side. (just select the proper bayer filter with MAX)

- If you select to output 32bit RGB, then the color decoding is done on the camera side.

In the first case, you reduce the amount of data the camera send to the PC (2048 x 2048 x 8 @ 56fps = 224Mb/s) but you increase the CPU load for decoding.

In the second case, you increase the amount of data, because color images are 32bit (2048 x 2048 x 32 @ 56fps = 896Mb/s) but you reduce the CPU load.

For your saving problem, check in your Vi Express that you have selected 32bit RGB image. I would suggest you to use the IMAQ create function wich allows you to create an image buffer and select the image mode (grayscale, or color etc)

Regards

[BlueCheese]

Hi.

As long as you change the bayer format inside the Express VI to "None", you should get a raw Bayer Mono8 image just like you are getting in MAX. You may need to dig into the attribute tree a little bit to access that setting.

Also, you are seeing expected behavior in the current version where the only decoding of Bayer formats (regardless of input depth) is into RGB32. The ability to decode 10/12/14/16-bit images into RGB64 is requested often and should be coming soon. 

Eric