gimpimageconvert: GIMP Library Reference Manual

+ + +

gimpimageconvert

gimpimageconvert — Conversions between RGB, indexed, and grayscale modes.

Functions

++++ + + + + + + + + + + + + + + + + + + + + + + +

+gboolean +	+gimp_image_convert_rgb () +
+gboolean +	+gimp_image_convert_grayscale () +
+gboolean +	+gimp_image_convert_indexed () +
+gboolean +	+gimp_image_convert_set_dither_matrix () +
+gboolean +	+gimp_image_convert_precision () +

Description

Conversions between RGB, indexed, and grayscale modes.

Functions

gimp_image_convert_rgb ()

gboolean
+gimp_image_convert_rgb (gint32 image_ID);

Convert specified image to RGB color

This procedure converts the specified image to RGB color. This +process requires an image in Grayscale or Indexed color mode. No +image content is lost in this process aside from the colormap for an +indexed image.

Parameters

+++++ + + + + + +

image_ID

The image.

Returns

TRUE on success.

gimp_image_convert_grayscale ()

gboolean
+gimp_image_convert_grayscale (gint32 image_ID);

Convert specified image to grayscale

This procedure converts the specified image to grayscale. This +process requires an image in RGB or Indexed color mode.

Parameters

+++++ + + + + + +

image_ID

The image.

Returns

TRUE on success.

gimp_image_convert_indexed ()

gboolean
+gimp_image_convert_indexed (gint32 image_ID,
+                            GimpConvertDitherType dither_type,
+                            GimpConvertPaletteType palette_type,
+                            gint num_cols,
+                            gboolean alpha_dither,
+                            gboolean remove_unused,
+                            const gchar *palette);

Convert specified image to and Indexed image

This procedure converts the specified image to 'indexed' color. This +process requires an image in RGB or Grayscale mode. The +'palette_type' specifies what kind of palette to use, A type of '0' +means to use an optimal palette of 'num_cols' generated from the +colors in the image. A type of '1' means to re-use the previous +palette (not currently implemented). A type of '2' means to use the +so-called WWW-optimized palette. Type '3' means to use only black +and white colors. A type of '4' means to use a palette from the gimp +palettes directories. The 'dither type' specifies what kind of +dithering to use. '0' means no dithering, '1' means standard +Floyd-Steinberg error diffusion, '2' means Floyd-Steinberg error +diffusion with reduced bleeding, '3' means dithering based on pixel +location ('Fixed' dithering).

Parameters

+++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +

image_ID	The image.
dither_type	The dither type to use.
palette_type	The type of palette to use.
num_cols	The number of colors to quantize to, ignored unless (palette_type == GIMP_CONVERT_PALETTE_GENERATE).
alpha_dither	Dither transparency to fake partial opacity.
remove_unused	Remove unused or duplicate color entries from final palette, ignored if (palette_type == GIMP_CONVERT_PALETTE_GENERATE).
palette	The name of the custom palette to use, ignored unless (palette_type == GIMP_CONVERT_PALETTE_CUSTOM).

Returns

TRUE on success.

gimp_image_convert_set_dither_matrix ()

gboolean
+gimp_image_convert_set_dither_matrix (gint width,
+                                      gint height,
+                                      gint matrix_length,
+                                      const guint8 *matrix);

Set dither matrix for conversion to indexed

This procedure sets the dither matrix used when converting images to +INDEXED mode with positional dithering.

Parameters

+++++ + + + + + + + + + + + + + + + + + + + + + + +

width	Width of the matrix (0 to reset to default matrix).
height	Height of the matrix (0 to reset to default matrix).
matrix_length	The length of 'matrix'.
matrix	The matrix -- all values must be >= 1.

Returns

TRUE on success.

Since: 2.4

gimp_image_convert_precision ()

gboolean
+gimp_image_convert_precision (gint32 image_ID,
+                              GimpPrecision precision);

Convert the image to the specified precision

This procedure converts the image to the specified precision. Note +that indexed images cannot be converted and are always in +GIMP_PRECISION_U8.

Parameters

+++++ + + + + + + + + + + + + +

image_ID	The image.
precision	The new precision.

Returns

TRUE on success.

Since: 2.10