ImageGear for C and C++ on Linux v19.10 - Updated
Reconstruct Camera Raw Images Using Custom Parameters
By default, ImageGear reconstructs Camera RAW images automatically, using the settings found in the image metadata. However, for some camera raw formats, ImageGear also allows you to use custom parameters for color reconstruction.
See Cameras Supported for DC RAW Formats for a list of cameras supported by ImageGear for DC RAW; the list includes information about the availability of custom color reconstruction.
The automatic color reconstruction process described below is also applicable to DNG images.
In order to apply custom color reconstruction to an image, you should first switch off all or some of the automatic color reconstruction operations. Use RECONSTRUCT_COLORS, APPLY_COLORSPACE_CONVERSION, and APPLY_TONE_CORRECTION control parameters of DCRAW, Headerless Digital Camera Raw, or DNG format filters for this.
If custom color reconstruction is not supported for an image, an attempt to read it using non-default settings of RECONSTRUCT_COLORS, APPLY_COLORSPACE_CONVERSION, or APPLY_TONE_CORRECTION control parameters will result in an ImageGear error.
In order to perform the custom color reconstruction, you will need to obtain the color reconstruction metadata from the images. See Manipulating Image Data for information about how to access the metadata. See DCRAW Non-Image Data Structure for information on specific metadata tags used for color reconstruction.
Specific stages of color reconstruction are discussed below.
In order to adjust image tone (contrast/brightness curve), set the "APPLY_TONE_CORRECTION" filter option to FALSE. This will tell ImageGear to skip the tone correction step. The application can create a Tone correction LUT using IG_IP_DCRaw_tone_LUT_build, or build its own Tone LUT. In order to convert the image to the standard sRGB color space, an additional sRGB Gamma LUT must be applied. Use IG_IP_DCRaw_RGB_gamma_LUT_build to build sRGB Gamma LUT.
Use IG_IP_transform_with_LUTs to apply a LUT to the image.
The APPLY_TONE_CORRECTION parameter only has effect if both APPLY_COLORSPACE_CONVERSION and RECONSTRUCT_COLORS options are TRUE.