RAW Image Format and Digital Negative are file formats of digital images containing all of the image data that has been captured by the sensor digital camera. RAW Image Format and Digital Negative (DNG) are not the same, but are often used wrongly to indicate the minimally processed image file formats of a Digital Camera.
RAW Image Format and Digital Negative
Adobe’s Open Source Digital Negative (DNG) format belongs the among the vast file extensions of RAW Image Format. The RAW Image format has generally means that compression of data has been applied without the loss of information. RAW Image Format files are sometimes called digital negatives, as they fulfill the same role as the negatives in film photography, but as because Digital Negative (DNG) is itself a sub of RAW Image Format, we logically can not use the terminology.
Understanding RAW Image Format
As because RAW Image Format contains all the image data captured by the camera and it has greater color depth (usually 36 to 48 bits / pixel ) the file size is too large. The major drawback of this format is the lack of standardization : each camera manufacturer uses its own version of the RAW Image Format, which can lead to incompatibilities or version of RAW Image Format that can not be used in the future. This is what to some extent has been solved by introduction of a Open Source RAW Image Format by Adobe – that is Digital Negative (DNG) format.
Advantages of RAW Image Format over JPEG format
It is a matter of fact that every camera does generate RAW Image Format at some step and then automatically convert to compressed JPEG format. In lower end digital cameras, this virtual ‘RAW Image Format’ is not stored, but in higher end digital cameras (especially the DSLRs) the user gets the option to save the RAW Image Format data on memory card, which can be transferred to a computer and then post processed using some software like Adobe Photoshop. Obviously, the processing on a computer, with an advanced image editor, by a human will not be the same that is done on the digital camera itself.
As RAW Image Format contains all the data captured by the camera, every elements of it can be effectively post processed without any distortion. Honestly, JPEG format can not be compared with RAW Image Format as it will be very crude comparison. JPEG format is just an output format of the RAW Image Format.