cfa_to_rgb — 将单通道颜色滤波阵列 CFA（Color Filter Array）图像转换为 RGB 图像。
cfa_to_rgb(CFAImage : RGBImage : CFAType, Interpolation : )
cfa_to_rgb converts a single-channel color filter array
image CFAImage into an RGB image RGBImage. Color
filter array images are typically generated by single-chip CCD
cameras. The conversion from color filter array image to RGB image
is typically done on the camera itself or is performed by the device
driver of the frame grabber that is used to grab the image. In some
cases, however, the device driver simply passes the color filter
array image through unchanged. In this case, the corresponding
HALCON frame grabber interface typically converts the image into an
RGB image. Hence, the operator cfa_to_rgb is normally used
if the images are not being grabbed using the HALCON frame grabber
interface (grab_image or grab_image_async), but are
grabbed using function calls from the frame grabber SDK, and are
passed to HALCON using gen_image1 or
gen_image1_extern。
In single-chip CCD cameras, a color filter array in front of the
sensor provides (subsampled) color information. The most frequently
used filter is the so-called Bayer filter. The color filter array
has the following layout in this case:
Each gray value of the input image CFAImage corresponds to
the brightness of the pixel behind the corresponding color filter.
Hence, in the above layout, the pixel (0,0) corresponds to a green
color value, while the pixel (0,1) corresponds to a blue color
value. The layout of the Bayer filter is completely determined by
the first two elements of the first row of the image, and can be
chosen with the parameter CFAType. In particular, this
enables the correct conversion of color filter array images that
have been cropped out of a larger image (e.g., using
crop_part or crop_rectangle1).
The algorithm that is used to interpolate the RGB values is
determined by the parameter Interpolation. For
Interpolation = 'bilinear', a bilinear
interpolation is performed. While this algorithm is very fast, it
typically leads to “zipper-like” artifacts and color artifacts at
strong edges. For Interpolation =
'bilinear_dir', a modified version of the bilinear
interpolation is performed that may lead to fewer zipper-like
artifacts, especially at horizontal or vertical edges in the image.
The results may still exhibit color artifacts at strong edges,
however. The runtime of this algorithm is only slightly longer than
that of bilinear interpolation. For Interpolation =
'bilinear_enhanced', an enhanced version of the bilinear
interpolation is performed that produces fewer zipper-like artifacts
and color artifacts than the other two bilinear algorithms in most
cases. The runtime of this algorithm is significantly longer than
that of the other two algorithms.
If 'mmx_enable' is set to 'true' (and the SIMD
instruction set is available), the internal calculations for byte
images are performed using SIMD technology for
Interpolation = 'bilinear' and
Interpolation = 'bilinear_dir'.
For Interpolation = 'bilinear' and
Interpolation = 'bilinear_dir', cfa_to_rgb
可在 OpenCL 设备上执行。输入图像的宽度对于 byte 图像应为 4 的倍数，对于 uint2 图像应为 2 的倍数，否则操作速度将大幅降低。
CFAImage (输入对象) singlechannelimage(-array) → object (byte* / uint2*) *允许用于计算设备
输入图像。
RGBImage (输出对象) multichannel-image(-array) → object (byte / uint2)
输出图像。
CFAType (输入控制) string → (string)
Color filter array type.
默认值： 'bayer_gb'
值列表： 'bayer_bg', 'bayer_gb', 'bayer_gr', 'bayer_rg'
Interpolation (输入控制) string → (string)
Interpolation type.
默认值： 'bilinear'
值列表： 'bilinear', 'bilinear_dir', 'bilinear_enhanced'
cfa_to_rgb 在所有参数正确时返回 2 ( H_MSG_TRUE )。当输入为空时，可设置行为通过算子 set_system(::'no_object_result', <Result>:)。如有必要，则抛出异常。
gen_image1_extern,
gen_image1,
grab_image
基础