raygeo.image.convert

Functions

rgba_to_binary()

rgba_to_binary(
    rgba: numpy.NDArray[numpy.uint8],
    width: int,
    height: int,
    stride: int,
    threshold: int = 128,
    invert: bool = False,
) -> numpy.NDArray[numpy.uint8]

Convert raw BGRA pixel buffer to binary image using thresholding.

Transparent pixels (alpha == 0) are always treated as white (0).

Parameter	Type	Description
rgba	numpy.NDArray[numpy.uint8]	Flattened uint8 buffer of shape (stride * height * 4,).
width	int	Image width in pixels.
height	int	Image height in pixels.
stride	int	Row stride in pixels.
threshold	int = 128	Brightness value (0-255) for binarization.
invert	bool = False	If True, pixels above threshold become black (1).
Returns	numpy.NDArray[numpy.uint8]	2D binary uint8 array (values 0 or 1) with shape (height, width).
Complexity		O(w*h)

rgba_to_grayscale()

rgba_to_grayscale(
    rgba: numpy.NDArray[numpy.uint8],
    width: int,
    height: int,
    stride: int,
) -> tuple[numpy.NDArray[numpy.uint8], numpy.NDArray[numpy.float32]]

Convert raw BGRA pixel buffer to grayscale with alpha unpremultiplication.

Performs proper unpremultiplication of alpha and blends to white background for grayscale calculation using BT.601 luminance weights.

Parameter	Type	Description
rgba	numpy.NDArray[numpy.uint8]	Flattened uint8 buffer of shape (stride * height * 4,).
width	int	Image width in pixels.
height	int	Image height in pixels.
stride	int	Row stride in pixels (may be larger than width).
Returns	tuple[numpy.NDArray[numpy.uint8], numpy.NDArray[numpy.float32]]	Tuple of (grayscale_uint8, alpha_float32) arrays, each (height, width).
Complexity		O(w*h)

rgba_to_grayscale_inplace()

rgba_to_grayscale_inplace(
    rgba: numpy.NDArray[numpy.uint8],
    width: int,
    height: int,
    stride: int,
) -> None

Convert raw BGRA pixel buffer to grayscale in place.

Modifies the buffer directly, converting BGR channels to grayscale while preserving the alpha channel.

Parameter	Type	Description
rgba	numpy.NDArray[numpy.uint8]	Flattened uint8 buffer of shape (stride * height * 4,).
width	int	Image width in pixels.
height	int	Image height in pixels.
stride	int	Row stride in pixels.
Returns	None
Complexity		O(w*h)