linear_trans_colorT_linear_trans_colorLinearTransColorLinearTransColorlinear_trans_color (Operator)

Name

linear_trans_colorT_linear_trans_colorLinearTransColorLinearTransColorlinear_trans_color — Compute an affine transformation of the color values of a multichannel image.

Signature

linear_trans_color(Image : ImageTrans : TransMat : )

Herror T_linear_trans_color(const Hobject Image, Hobject* ImageTrans, const Htuple TransMat)

void LinearTransColor(const HObject& Image, HObject* ImageTrans, const HTuple& TransMat)

HImage HImage::LinearTransColor(const HTuple& TransMat) const

static void HOperatorSet.LinearTransColor(HObject image, out HObject imageTrans, HTuple transMat)

HImage HImage.LinearTransColor(HTuple transMat)

def linear_trans_color(image: HObject, trans_mat: Sequence[float]) -> HObject

Description

linear_trans_colorlinear_trans_colorLinearTransColorLinearTransColorLinearTransColorlinear_trans_color performs an affine transformation of the color values of the multichannel image ImageImageImageImageimageimage and returns the result in ImageTransImageTransImageTransImageTransimageTransimage_trans. The affine transformation of the color values is described by the transformation matrix TransMatTransMatTransMatTransMattransMattrans_mat. If n is the number of channels in ImageImageImageImageimageimage and m is the number of channels in ImageTransImageTransImageTransImageTransimageTransimage_trans, TransMatTransMatTransMatTransMattransMattrans_mat is a homogeneous m × (n+1) matrix that is stored row by row. Homogeneous means that the left m × n submatrix of TransMatTransMatTransMatTransMattransMattrans_mat describes a linear transformation of the color values, while the last column of TransMatTransMatTransMatTransMattransMattrans_mat describes a constant offset of the color values. The transformation matrix is typically computed with gen_principal_comp_transgen_principal_comp_transGenPrincipalCompTransGenPrincipalCompTransGenPrincipalCompTransgen_principal_comp_trans. In particular, it is possible to project an image onto the first m principal components by selecting the first m × (n+1) values of the transformation returned by gen_principal_comp_transgen_principal_comp_transGenPrincipalCompTransGenPrincipalCompTransGenPrincipalCompTransgen_principal_comp_trans. The transformation can, however, also be specified directly. For example, a transformation from RGB to YIQ, which is described by the following transformation can be achieved by setting TransMatTransMatTransMatTransMattransMattrans_mat to [0.299,0.587,0.114,0.0,0.599,-0.276,-0.324,127.5,0.214,-0.522,0.309,127.5] Here, it should be noted that the above transformation is unnormalized, i.e., the resulting color values can lie outside the range [0,255]. The transformation 'yiq'"yiq""yiq""yiq""yiq""yiq" in trans_from_rgbtrans_from_rgbTransFromRgbTransFromRgbTransFromRgbtrans_from_rgb additionally scales the rows of the matrix (except for the constant offset) appropriately.

To avoid a loss of information, linear_trans_colorlinear_trans_colorLinearTransColorLinearTransColorLinearTransColorlinear_trans_color returns an image of type real. If a different image type is desired, the image can be transformed with convert_image_typeconvert_image_typeConvertImageTypeConvertImageTypeConvertImageTypeconvert_image_type.

Attention

linear_trans_colorlinear_trans_colorLinearTransColorLinearTransColorLinearTransColorlinear_trans_color can be executed on OpenCL devices if the image ImageImageImageImageimageimage consists of nine channels or less and is transformed to an image of three channels or less. Since the calculations are done in single precision floating point, the results may differ from those calculated by the CPU.

Execution Information

Parameters

ImageImageImageImageimageimage (input_object)  multichannel-image(-array) objectHImageHObjectHImageHobject (byte / direction / cyclic / int1 / int2 / uint2 / int4 / real)

Multichannel input image.

ImageTransImageTransImageTransImageTransimageTransimage_trans (output_object)  multichannel-image(-array) objectHImageHObjectHImageHobject * (real)

Multichannel output image.

TransMatTransMatTransMatTransMattransMattrans_mat (input_control)  real-array HTupleSequence[float]HTupleHtuple (real) (double) (double) (double)

Transformation matrix for the color values.

Result

The operator linear_trans_colorlinear_trans_colorLinearTransColorLinearTransColorLinearTransColorlinear_trans_color returns the value TRUE if the parameters are correct. Otherwise an exception is raised.

Possible Predecessors

gen_principal_comp_transgen_principal_comp_transGenPrincipalCompTransGenPrincipalCompTransGenPrincipalCompTransgen_principal_comp_trans

Possible Successors

convert_image_typeconvert_image_typeConvertImageTypeConvertImageTypeConvertImageTypeconvert_image_type

Alternatives

principal_compprincipal_compPrincipalCompPrincipalCompPrincipalCompprincipal_comp, trans_from_rgbtrans_from_rgbTransFromRgbTransFromRgbTransFromRgbtrans_from_rgb, trans_to_rgbtrans_to_rgbTransToRgbTransToRgbTransToRgbtrans_to_rgb

Module

Foundation