libvips

vips_colourspace_issupported ()

gboolean
vips_colourspace_issupported (const VipsImage *image);

Test if image is in a colourspace that vips_colourspace() can process.

[method]

vips_colourspace ()

int
vips_colourspace (VipsImage *in,
                  VipsImage **out,
                  VipsInterpretation space,
                  ...);

Optional arguments:

This operation looks at the interpretation field of in (or uses source_space , if set) and runs a set of colourspace conversion functions to move it to space .

For example, given an image tagged as VIPS_INTERPRETATION_YXY, running vips_colourspace() with space set to VIPS_INTERPRETATION_LAB will convert with vips_Yxy2XYZ() and vips_XYZ2Lab().

See also: vips_colourspace_issupported(), vips_image_guess_interpretation().

[method]

vips_LabQ2sRGB ()

int
vips_LabQ2sRGB (VipsImage *in,
                VipsImage **out,
                ...);

Unpack a LabQ (VIPS_CODING_LABQ) image to a three-band short image.

See also: vips_LabS2LabQ(), vips_LabQ2sRGB(), vips_rad2float().

[method]

vips_rad2float ()

int
vips_rad2float (VipsImage *in,
                VipsImage **out,
                ...);

Unpack a RAD (VIPS_CODING_RAD) image to a three-band float image.

See also: vips_float2rad(), vips_LabQ2LabS().

[method]

vips_float2rad ()

int
vips_float2rad (VipsImage *in,
                VipsImage **out,
                ...);

Convert a three-band float image to Radiance 32-bit packed format.

See also: vips_rad2float(), VIPS_CODING_RAD, vips_LabQ2Lab().

[method]

vips_LabS2LabQ ()

int
vips_LabS2LabQ (VipsImage *in,
                VipsImage **out,
                ...);

Convert a LabS three-band signed short image to LabQ

See also: vips_LabQ2LabS().

[method]

vips_LabQ2LabS ()

int
vips_LabQ2LabS (VipsImage *in,
                VipsImage **out,
                ...);

Unpack a LabQ (VIPS_CODING_LABQ) image to a three-band short image.

See also: vips_LabS2LabQ(), vips_LabQ2LabS(), vips_rad2float().

[method]

vips_LabQ2Lab ()

int
vips_LabQ2Lab (VipsImage *in,
               VipsImage **out,
               ...);

Unpack a LabQ (VIPS_CODING_LABQ) image to a three-band float image.

See also: vips_LabQ2Lab(), vips_LabQ2LabS(), vips_rad2float().

[method]

vips_Lab2LabQ ()

int
vips_Lab2LabQ (VipsImage *in,
               VipsImage **out,
               ...);

Convert a Lab three-band float image to LabQ (VIPS_CODING_LABQ).

See also: vips_LabQ2Lab().

[method]

vips_LCh2Lab ()

int
vips_LCh2Lab (VipsImage *in,
              VipsImage **out,
              ...);

Turn LCh to Lab.

[method]

vips_Lab2LCh ()

int
vips_Lab2LCh (VipsImage *in,
              VipsImage **out,
              ...);

Turn Lab to LCh.

[method]

vips_Yxy2Lab ()

int
vips_Yxy2Lab (VipsImage *in,
              VipsImage **out,
              ...);

vips_CMC2XYZ ()

int
vips_CMC2XYZ (VipsImage *in,
              VipsImage **out,
              ...);

vips_Lab2XYZ ()

int
vips_Lab2XYZ (VipsImage *in,
              VipsImage **out,
              ...);

Optional arguments:

Turn Lab to XYZ. The colour temperature defaults to D65, but can be specified with temp .

[method]

vips_XYZ2Lab ()

int
vips_XYZ2Lab (VipsImage *in,
              VipsImage **out,
              ...);

Optional arguments:

Turn XYZ to Lab, optionally specifying the colour temperature. temp defaults to D65.

[method]

vips_XYZ2scRGB ()

int
vips_XYZ2scRGB (VipsImage *in,
                VipsImage **out,
                ...);

Turn XYZ to scRGB.

[method]

vips_scRGB2sRGB ()

int
vips_scRGB2sRGB (VipsImage *in,
                 VipsImage **out,
                 ...);

Optional arguments:

Convert an scRGB image to sRGB. Set depth to 16 to get 16-bit output.

If depth is 16, any extra channels after RGB are multiplied by 256.

See also: vips_LabS2LabQ(), vips_sRGB2scRGB(), vips_rad2float().

[method]

vips_scRGB2BW ()

int
vips_scRGB2BW (VipsImage *in,
               VipsImage **out,
               ...);

Optional arguments:

Convert an scRGB image to greyscale. Set depth to 16 to get 16-bit output.

If depth is 16, any extra channels after RGB are multiplied by 256.

See also: vips_LabS2LabQ(), vips_sRGB2scRGB(), vips_rad2float().

[method]

vips_sRGB2scRGB ()

int
vips_sRGB2scRGB (VipsImage *in,
                 VipsImage **out,
                 ...);

Convert an sRGB image to scRGB. The input image can be 8 or 16-bit.

If the input image is tagged as VIPS_INTERPRETATION_RGB16, any extra channels after RGB are divided by 256. Thus, scRGB alpha is always 0 - 255.99.

See also: vips_scRGB2XYZ(), vips_scRGB2sRGB(), vips_rad2float().

[method]

vips_scRGB2XYZ ()

int
vips_scRGB2XYZ (VipsImage *in,
                VipsImage **out,
                ...);

Turn XYZ to scRGB.

[method]

vips_HSV2sRGB ()

int
vips_HSV2sRGB (VipsImage *in,
               VipsImage **out,
               ...);

Convert HSV to sRGB.

HSV is a crude polar coordinate system for RGB images. It is provided for compatibility with other image processing systems. See vips_Lab2LCh() for a much better colour space.

See also: vips_sRGB2HSV().

[method]

vips_sRGB2HSV ()

int
vips_sRGB2HSV (VipsImage *in,
               VipsImage **out,
               ...);

Convert to HSV.

HSV is a crude polar coordinate system for RGB images. It is provided for compatibility with other image processing systems. See vips_Lab2LCh() for a much better colour space.

See also: vips_HSV2sRGB(), vips_Lab2LCh().

[method]

vips_LCh2CMC ()

int
vips_LCh2CMC (VipsImage *in,
              VipsImage **out,
              ...);

Turn LCh to CMC.

The CMC colourspace is described in "Uniform Colour Space Based on the CMC(l:c) Colour-difference Formula", M R Luo and B Rigg, Journal of the Society of Dyers and Colourists, vol 102, 1986. Distances in this colourspace approximate, within 10% or so, differences in the CMC(l:c) colour difference formula.

This operation generates CMC(1:1). For CMC(2:1), halve Lucs and double Cucs.

See also: vips_CMC2LCh().

[method]

vips_CMC2LCh ()

int
vips_CMC2LCh (VipsImage *in,
              VipsImage **out,
              ...);

Turn LCh to CMC.

See also: vips_LCh2CMC().

[method]

vips_XYZ2Yxy ()

int
vips_XYZ2Yxy (VipsImage *in,
              VipsImage **out,
              ...);

Turn XYZ to Yxy.

[method]

vips_Yxy2XYZ ()

int
vips_Yxy2XYZ (VipsImage *in,
              VipsImage **out,
              ...);

Turn XYZ to Yxy.

[method]

vips_LabS2Lab ()

int
vips_LabS2Lab (VipsImage *in,
               VipsImage **out,
               ...);

Convert a LabS three-band signed short image to a three-band float image.

See also: vips_LabS2Lab().

[method]

vips_Lab2LabS ()

int
vips_Lab2LabS (VipsImage *in,
               VipsImage **out,
               ...);

Turn Lab to LabS, signed 16-bit int fixed point.

See also: vips_LabQ2Lab().

[method]

vips_CMYK2XYZ ()

int
vips_CMYK2XYZ (VipsImage *in,
               VipsImage **out,
               ...);

Turn CMYK to XYZ. If the image has an embedded ICC profile this will be used for the conversion. If there is no embedded profile, a generic fallback profile will be used.

Conversion is to D65 XYZ with relative intent. If you need more control over the process, use vips_icc_import() instead.

[method]

vips_XYZ2CMYK ()

int
vips_XYZ2CMYK (VipsImage *in,
               VipsImage **out,
               ...);

Turn XYZ to CMYK.

Conversion is from D65 XYZ with relative intent. If you need more control over the process, use vips_icc_export() instead.

[method]

vips_profile_load ()

int
vips_profile_load (const char *name,
                   VipsBlob **profile,
                   ...);

Load a named profile.

Profiles are loaded from four sources:

vips_icc_present ()

int
vips_icc_present (void);

VIPS can optionally be built without the ICC library. Use this function to test for its availability.

vips_icc_transform ()

int
vips_icc_transform (VipsImage *in,
                    VipsImage **out,
                    const char *output_profile,
                    ...);

Optional arguments:

Transform an image with a pair of ICC profiles. The input image is moved to profile-connection space with the input profile and then to the output space with the output profile.

The input profile is searched for in three places:

If black_point_compensation is set, LCMS black point compensation is enabled.

depth defaults to 8, or 16 if in is a 16-bit image.

The output image has the output profile attached to the VIPS_META_ICC_NAME field.

Use vips_icc_import() and vips_icc_export() to do either the first or second half of this operation in isolation.

[method]

vips_icc_import ()

int
vips_icc_import (VipsImage *in,
                 VipsImage **out,
                 ...);

Optional arguments:

Import an image from device space to D65 LAB with an ICC profile. If pcs is set to VIPS_PCS_XYZ, use CIE XYZ PCS instead.

The input profile is searched for in three places:

If black_point_compensation is set, LCMS black point compensation is enabled.

[method]

vips_icc_export ()

int
vips_icc_export (VipsImage *in,
                 VipsImage **out,
                 ...);

Optional arguments:

Export an image from D65 LAB to device space with an ICC profile. If pcs is set to VIPS_PCS_XYZ, use CIE XYZ PCS instead. If output_profile is not set, use the embedded profile, if any. If output_profile is set, export with that and attach it to the output image.

If black_point_compensation is set, LCMS black point compensation is enabled.

[method]

vips_icc_ac2rc ()

int
vips_icc_ac2rc (VipsImage *in,
                VipsImage **out,
                const char *profile_filename);

Transform an image from absolute to relative colorimetry using the MediaWhitePoint stored in the ICC profile.

See also: vips_icc_transform(), vips_icc_import().

[method]

vips_icc_is_compatible_profile ()

gboolean
vips_icc_is_compatible_profile (VipsImage *image,
                                const void *data,
                                size_t data_length);

vips_dE76 ()

int
vips_dE76 (VipsImage *left,
           VipsImage *right,
           VipsImage **out,
           ...);

Calculate dE 76.

vips_dE00 ()

int
vips_dE00 (VipsImage *left,
           VipsImage *right,
           VipsImage **out,
           ...);

Calculate dE 00.

vips_dECMC ()

int
vips_dECMC (VipsImage *left,
            VipsImage *right,
            VipsImage **out,
            ...);

Calculate dE CMC. The input images are transformed to CMC colour space and the euclidean distance between corresponding pixels calculated.

To calculate a colour difference with values for (l:c) other than (1:1), transform the two source images to CMC yourself, scale the channels appropriately, and call this function.

See also: vips_colourspace()

vips_col_Lab2XYZ ()

void
vips_col_Lab2XYZ (float L,
                  float a,
                  float b,
                  float *X,
                  float *Y,
                  float *Z);

Calculate XYZ from Lab, D65.

See also: vips_Lab2XYZ().

vips_col_XYZ2Lab ()

void
vips_col_XYZ2Lab (float X,
                  float Y,
                  float Z,
                  float *L,
                  float *a,
                  float *b);

Calculate XYZ from Lab, D65.

See also: vips_XYZ2Lab().

vips_col_ab2h ()

double
vips_col_ab2h (double a,
               double b);

vips_col_ab2Ch ()

void
vips_col_ab2Ch (float a,
                float b,
                float *C,
                float *h);

vips_col_Ch2ab ()

void
vips_col_Ch2ab (float C,
                float h,
                float *a,
                float *b);

Calculate ab from Ch, h in degrees.

vips_col_L2Lcmc ()

float
vips_col_L2Lcmc (float L);

Calculate Lcmc from L.

vips_col_C2Ccmc ()

float
vips_col_C2Ccmc (float C);

Calculate Ccmc from C.

vips_col_Ch2hcmc ()

float
vips_col_Ch2hcmc (float C,
                  float h);

Calculate hcmc from C and h.

vips_col_make_tables_CMC ()

void
vips_col_make_tables_CMC (void);

Make the lookup tables for cmc.

vips_col_Lcmc2L ()

float
vips_col_Lcmc2L (float Lcmc);

Calculate L from Lcmc using a table. Call vips_col_make_tables_CMC() at least once before using this function.

vips_col_Ccmc2C ()

float
vips_col_Ccmc2C (float Ccmc);

Calculate C from Ccmc using a table. Call vips_col_make_tables_CMC() at least once before using this function.

vips_col_Chcmc2h ()

float
vips_col_Chcmc2h (float C,
                  float hcmc);

Calculate h from C and hcmc, using a table. Call vips_col_make_tables_CMC() at least once before using this function.

vips_col_sRGB2scRGB_8 ()

int
vips_col_sRGB2scRGB_8 (int r,
                       int g,
                       int b,
                       float *R,
                       float *G,
                       float *B);

vips_col_sRGB2scRGB_16 ()

int
vips_col_sRGB2scRGB_16 (int r,
                        int g,
                        int b,
                        float *R,
                        float *G,
                        float *B);

vips_col_sRGB2scRGB_8_noclip ()

int
vips_col_sRGB2scRGB_8_noclip (int r,
                              int g,
                              int b,
                              float *R,
                              float *G,
                              float *B);

vips_col_sRGB2scRGB_16_noclip ()

int
vips_col_sRGB2scRGB_16_noclip (int r,
                               int g,
                               int b,
                               float *R,
                               float *G,
                               float *B);

vips_col_scRGB2XYZ ()

int
vips_col_scRGB2XYZ (float R,
                    float G,
                    float B,
                    float *X,
                    float *Y,
                    float *Z);

Turn scRGB into XYZ.

See also: vips_scRGB2XYZ().

vips_col_XYZ2scRGB ()

int
vips_col_XYZ2scRGB (float X,
                    float Y,
                    float Z,
                    float *R,
                    float *G,
                    float *B);

Turn XYZ into scRGB.

See also: vips_XYZ2scRGB().

vips_col_scRGB2sRGB_8 ()

int
vips_col_scRGB2sRGB_8 (float R,
                       float G,
                       float B,
                       int *r,
                       int *g,
                       int *b,
                       int *og);

vips_col_scRGB2sRGB_16 ()

int
vips_col_scRGB2sRGB_16 (float R,
                        float G,
                        float B,
                        int *r,
                        int *g,
                        int *b,
                        int *og);

vips_col_scRGB2BW_16 ()

int
vips_col_scRGB2BW_16 (float R,
                      float G,
                      float B,
                      int *g,
                      int *og);

vips_col_scRGB2BW_8 ()

int
vips_col_scRGB2BW_8 (float R,
                     float G,
                     float B,
                     int *g,
                     int *og);

vips_pythagoras ()

float
vips_pythagoras (float L1,
                 float a1,
                 float b1,
                 float L2,
                 float a2,
                 float b2);

Pythagorean distance between two points in colour space. Lab/XYZ/CMC etc.

vips_col_dE00 ()

float
vips_col_dE00 (float L1,
               float a1,
               float b1,
               float L2,
               float a2,
               float b2);

CIEDE2000, from:

Luo, Cui, Rigg, "The Development of the CIE 2000 Colour-Difference Formula: CIEDE2000", COLOR research and application, pp 340

VIPS_D93_X0

#define VIPS_D93_X0 (89.7400)

Areas under curves for D93, 2 degree observer.

VIPS_D93_Y0

#define VIPS_D93_Y0 (100.0)

VIPS_D93_Z0

#define VIPS_D93_Z0 (130.7700)

VIPS_D75_X0

#define VIPS_D75_X0 (94.9682)

Areas under curves for D75, 2 degree observer.

VIPS_D75_Y0

#define VIPS_D75_Y0 (100.0)

VIPS_D75_Z0

#define VIPS_D75_Z0 (122.5710)

VIPS_D65_X0

#define VIPS_D65_X0 (95.0470)

Areas under curves for D65, 2 degree observer.

VIPS_D65_Y0

#define VIPS_D65_Y0 (100.0)

VIPS_D65_Z0

#define VIPS_D65_Z0 (108.8827)

VIPS_D55_X0

#define VIPS_D55_X0 (95.6831)

Areas under curves for D55, 2 degree observer.

VIPS_D55_Y0

#define VIPS_D55_Y0 (100.0)

VIPS_D55_Z0

#define VIPS_D55_Z0 (92.0871)

VIPS_D50_X0

#define VIPS_D50_X0 (96.4250)

Areas under curves for D50, 2 degree observer.

VIPS_D50_Y0

#define VIPS_D50_Y0 (100.0)

VIPS_D50_Z0

#define VIPS_D50_Z0 (82.4680)

VIPS_A_X0

#define VIPS_A_X0 (109.8503)

Areas under curves for illuminant A (2856K), 2 degree observer.

VIPS_A_Y0

#define VIPS_A_Y0 (100.0)

VIPS_A_Z0

#define VIPS_A_Z0 (35.5849)

VIPS_B_X0

#define VIPS_B_X0 (99.0720)

Areas under curves for illuminant B (4874K), 2 degree observer.

VIPS_B_Y0

#define VIPS_B_Y0 (100.0)

VIPS_B_Z0

#define VIPS_B_Z0 (85.2230)

VIPS_C_X0

#define VIPS_C_X0 (98.0700)

Areas under curves for illuminant C (6774K), 2 degree observer.

VIPS_C_Y0

#define VIPS_C_Y0 (100.0)

VIPS_C_Z0

#define VIPS_C_Z0 (118.2300)

VIPS_E_X0

#define VIPS_E_X0 (100.0)

Areas under curves for equal energy illuminant E.

VIPS_E_Y0

#define VIPS_E_Y0 (100.0)

VIPS_E_Z0

#define VIPS_E_Z0 (100.0)

VIPS_D3250_X0

#define VIPS_D3250_X0 (105.6590)

Areas under curves for black body at 3250K, 2 degree observer.

VIPS_D3250_Y0

#define VIPS_D3250_Y0 (100.0)

VIPS_D3250_Z0

#define VIPS_D3250_Z0 (45.8501)

enum VipsIntent

The rendering intent. VIPS_INTENT_ABSOLUTE is best for scientific work, VIPS_INTENT_RELATIVE is usually best for accurate communication with other imaging libraries.

enum VipsPCS

Pick a Profile Connection Space for vips_icc_import() and vips_icc_export(). LAB is usually best, XYZ can be more convenient in some cases.