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The LEAD Color Conversion toolkit provides emulation tables as one of its conversion methods. This method however is provided only for the following conversions:
The Emulation tables' method supports both built-in and custom options. For built-in emulation tables, use the USE_ET option. The custom emulation tables' option, USE_CUSTOM_ET, provides custom conversion using user-supplied images, converted from the source images distributed with the library, by any tool, as follows:
| Conversion | Source | Convert to |
|---|---|---|
| CMYK to RGB | src_cmyk_image.tif | RGB image (i.e. dst_cmyk2rgb_image.tif) |
| RGB to Lab | src_rgb_image.tif | Lab image (i.e. dst_rgb2lab_image.tif) |
| Lab to RGB | src_lab_image.tif | RGB image (i.e. dst_lab2rgb_image.tif) |
A set of images, already converted and ready for use (dst_cmyk2rgb_image.tif, dst_rgb2lab_image.tif, and dst_lab2rgb_image.tif), is provided. However, using the provided set of converted images will produce the same results as the built-in emulation tables.
The code below shows how a conversion can be done using the built-in tables:
L_VOID Tables_Convert_CMYKToRGB(L_UCHAR *pInput, L_UCHAR *pOutput, L_INT nWidth, L_INT nHeight){LColor clr; /*Color Conversion object*/CONVERSION_PARAMS params; /*Conversion options*//* Zero initialize, this step is important*/ZeroMemory ( ¶ms, sizeof(CONVERSION_PARAMS));/*Conversion with options.The conversion will be done with the options specified in theparams variable*//* Set the params size */params.uStructSize = sizeof(CONVERSION_PARAMS);/* We want to use built-in emulation tables */params.nMethod = USE_ET;/* set the active conversion method */params.nActiveMethod = USE_ET;/* initialize the color conversion */clr.Initialize (CCS_CMYK, /*input color space*/CCS_RGB, /*output color space*/¶ms /*pointer to the initialization options*/);/* Convert the image buffer */clr.Convert (pInput, /* input buffer*/pOutput, /* output buffer*/nWidth, /*pixel's width*/nHeight, /*pixel's height*/0, /* 0 bytes align*/0); /*0 bytes align*//* free the conversion */clr.Free ();}
The code below shows how a conversion can be done using user-defined tables:
L_VOID Tables_Convert_CMYKToRGB(L_UCHAR *pInput, L_UCHAR *pOutput, L_INT nWidth, L_INT nHeight){LColor clr; /*Color Conversion object*/CONVERSION_PARAMS params; /*Conversion options*/ZeroMemory(¶ms, sizeof(CONVERSION_PARAMS));/*Conversion with options.The conversion will be done with the options specified in theparams variable*//* set the params size */params.uStructSize = sizeof(CONVERSION_PARAMS);/* we want to use custom emulation tables */params.nMethod = USE_CUSTOM_ET;/* set the active conversion method */params.nActiveMethod = USE_CUSTOM_ET;/* set the emulation tables */lstrcpy(params.sDstInputTable, TEXT("C:\\RGBImage.tif"));/* initialize the color conversion */clr.Initialize (CCS_CMYK, /*input color space*/CCS_RGB, /*output color space*/¶ms /*pointer to the initialization options*/);/* convert the image buffer */clr.Convert (pInput, /* input buffer */pOutput, /* output buffer */nWidth, /*pixel's width*/nHeight, /*pixel's height*/0, /* 0 bytes align*/0); /*0 bytes align*//* free the conversion */clr.Free ();}