| Full Name | Digital Negative file format |
| Format ID | IG_FORMAT_DNG = 108 |
| File Extension(s) | *.dng |
| Data Type | Raster image |
| Data Encoding | Binary |
| ImageGear Multipage Support | No |
| ImageGear Alpha Channel Support | No |
| ImageGear Platforms Support | WIN32, WIN64, Unix, Unix64, MAC |
ImageGear Supported Versions:
- Version 1.0.0.0
- Version 1.1.0.0 - fixed incompatibility in JPEG Lossless compression, added new tags
ImageGear Supported Features:
- IG_FLTR_DETECTSUPPORT - autodetection
- IG_FLTR_PAGEREADSUPPORT - single page file reading
ImageGear Read Support:
- IG_COMPRESSION_NONE:
- Grayscale: 9..16 bpp
- RGB: 24, 48 bpp *
- IG_COMPRESSION_JPEG:
- Grayscale: 16 bpp
- RGB: 24, 48 bpp *
* 8bpc DNG loading has been enabled via promoting the image to 16bpc before loading.
ImageGear Write Support:
None
ImageGear Filter Control Parameters:
| Filter Control Parameter | Type | Default Value | Available Values | Description |
| APPLY_COLORSPACE_CONVERSION | AT_BOOL | TRUE | TRUE, FALSE | Set to TRUE to convert raw image to linear sRGB color space during loading. Has effect only if RECONSTRUCT_COLORS is TRUE. |
| APPLY_TONE_CORRECTION | AT_BOOL | TRUE | TRUE, FALSE | Set to TRUE to automatically adjust image tone and apply sRGB gamma correction during loading. Has effect only if bothRECONSTRUCT_COLORS and APPLY_COLORSPACE_CONVERSION are TRUE. |
| RECONSTRUCT_COLORS | AT_BOOL | TRUE | TRUE, FALSE | ImageGear attempts to reconstruct full color image from the camera raw image. Otherwise, ImageGear loads raw pixel data without any processing. |
Comments
This file format was developed by Adobe as a non-proprietary format for unified storage of "raw" images from digital cameras. DNG image stores unprocessed pixel data obtained from camera's sensor, and keeps information about color, contrast and brightness adjustments, sharpening, as well as many other parameters, in its tags. This provides greater possibilities for image correction and enhancement, compared to commonly used formats such as JPEG, EXIF or TIFF.
The fact that the format is non-proprietary allows software vendors to provide support for DNG in their applications, with complete control over the image reconstruction process.
DNG extends TIFF/EP format. It adds a set of new tags for parameters that control reconstruction of full color image from the raw data.
References Used
ADOBE SYSTEMS INCORPORATED. Digital Negative (DNG) specification.