Herd Software Development
DaVinci Graphics Library
DaVinci Documentation

Filter method

Declaration

procedure Filter(FilterType: Cardinal);

Description

This performs a filtering operation on the currently loaded DIB. FilterType can be any of the following values. Filter operations are actually performed by Leonardo, and descriptions of the various filters are linked to each filter's description.

Constant Value Filter operation executed

IMFILTER_SHARPEN 1 Enhances the sharpness of the image; synthetic method of sharpening image focus. (Executes CreateSharpenedDIB)

IMFILTER_BLUR 2 Synthetically "softens" the image, similar to "Vaseline filtering" of a camera lense or deliberate out-of-focus photography. (Executes CreateFIRFilteredDIB)

IMFILTER_BRIGHTEN 3 Evenly increases the intensity of red, green and blue values for all pixels based on a percentage of current value. Similar to widening camera aperture. (Executes CreateFIRFilteredDIB)

IMFILTER_DARKEN 4 Evenly decreases the intensity of red, green and blue values for all pixels based on a percentage of current value. Similar to narrowing camera aperture. (Executes CreateFIRFilteredDIB)

IMFILTER_GRAYSCALE 5 Converts the image to grayscale. Executes GrayScaleDIB (convert into gray shades))

IMFILTER_DITHER8 6 Applies Floyd-Steinberg (high-quality) dithering to reduce the image's color depth to max. 256 colors using an optimized color palette. (Executes DIBSelectColors and DitherTo8)

IMFILTER_DITHER8N 7 Applies Floyd-Steinberg (high-quality) dithering to reduce the image's color depth to 256 colors, but uses the standard Windows 256 color palette. (Executes DitherTo8)

IMFILTER_DITHER4 8 Applies Floyd-Steinberg (high-quality) dithering to reduce the image's color depth to max. 16 colors using the standard VGA 16 color palette. (Executes DitherTo4) Note that the standard VGA color palette may not be identical to the palette used by your video driver currently in use.

IMFILTER_DITHER1 9 Applies Floyd-Steinberg (high-quality) dithering to reduce the image's color depth to max. 2 colors (monochrome) using black and white a the two colors. (Executes DitherTo1)

IMFILTER_BITCOUNT1 10 Reduces colour depth to monochrome (2 colors), no dithering. (Executes ConvertDIB)

IMFILTER_BITCOUNT4 11 Reduces or increases colour depth to 16 colors, no dithering. (Executes ConvertDIB)

IMFILTER_BITCOUNT8 12 Reduces or increases colour depth to 256 colors, no dithering. (Executes ConvertDIB)

IMFILTER_BITCOUNT16 13 Reduces or increases colour depth to HiColor (32K colors), no dithering. (Executes ConvertDIB)

IMFILTER_BITCOUNT24 14 Reduces or increases colour depth to TrueColor (16M colors), no dithering. (Executes ConvertDIB)

IMFILTER_BITCOUNT32 15 Increases colour depth to 32 bit color, (visually equivalent to TrueColor) no dithering. (Executes ConvertDIB)