Color Correction Matrix

A high color fidelity is required especially in the area of broadcast, medicine and microscopy, where images are displayed. The same conditions apply for visual printed image controls. For all camera families, MATRIX VISION strikes out in a new direction.

Since mvIMPACT Acquire version 1.12.50, there is the host based option "Color Twist" for the mvBlueFOX camera families available. This option consists of three separate 3 x 3 matrices:

  • The Color Correction Matrix with sensor specific correction coefficients.
  • A new parameter for the color saturation, effective for all image formats (RGB and YUV).
  • The choice of a display color space.

A result matrix is calculated from these three matrices. This matrix is used in the linear part of the signal path. We measure all sensors of all camera families step by step and determine the spectral characteristic in our measuring lab. The Color Correction Matrix is used to adapt the sensor characteristic to the spectral characteristic of the human eye.

tl_files/mv11/Newsletter/2012/Color_correction_sample_formula.jpg

High-quality and high color fidelity displaying on different monitors is possible with both, the display color space (normally sRGB; however, it is possible to select different common higher quality gamuts) and the common so-called viewing gamma of 2.2. We use the well-known standard color chart to verificate our results using a "before and after"- / "target and actual"-comparison. The following figure shows a CCD sensor just before a correction: Left actual, Right target

tl_files/mv11/Newsletter/2012/Color_correction_sample.jpg

Since firmware version 1.4, MATRIX VISION also offers a camera based enhanced color functionality for the mvBlueCOUGAR-X GigE Vision camera family. For this purpose, the GigE Vision standard option "Color Transformation Matrix" is used. This option makes it possible to enter 9 coefficients and 3 offset values for one RGB(in) → RGB(out) transformation. In combination with the Color Twist result matrix, now this option is available in the camera.

Advantage: No host CPU load, low latency, higher bit depth.

Back