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 p.1 #10 · Why don't DSLRs output TIFFs? | |
At the moment http://en.wikipedia.org/wiki/JPEG_XR (formerly HD Photo)looks good, I have posted in the past about wanting a file format that can handle in-camera HDR images without loosing so much data as jpg does.
Support for more color accuracy
In image and graphics representations, the color associated with each point in the picture (called a pixel) is represented as a set of numbers. Each color can be expressed as a combination of numbers that each represent the intensity of one of the components of a color (known as the channel) which consists of Red, Green and Blue (the three colors of light) color primary. Such a color scheme is called the RGB color model. Using an alternative set of color primaries, graphic files may treat the color of each point as a combination of Cyan, Magenta, Yellow, and Black (the four ink colors of printers) and therefore store the color of each point in four channels. Such a color scheme is called the CMYK color model. When the image being stored contains only black, white and shades of gray as colors, the image may be represented using a single grayscale channel for each pixel that only represents the intensity of the gray shade.
JPEG supports 24-Bit RGB (also known as truecolor): This representation stores each channel as an 8-bit number, an integer number from 0 to 255. In this case, the greater the number, the more intense the color component is. For instance, 25 in red channel represents dark red while 255 indicates fully vibrant red. This enables more than 16 million color possibilities. JPEG also supports 8-bit grayscale scheme, so that each pixel can have one of 256 possible shades of gray.
Also supported is 15-Bit and 16-Bit RGB (also known as Highcolor), along with 30-Bit RGB.
JPEG XR adds supports for 48-bit integer RGB (also known as deep color): This representation stores the values of each of the three channels as a 16-bit number, an integer number from 0 to 65,535, where 0 denotes least intensity and 65535 the greatest. Therefore, each channel stores a much finer grade of intensity.
JPEG XR also supports 16-bit per component (64-bit per pixel) integer CMYK color model.[12]
16-bit and 32-bit fixed point color component codings are also supported in JPEG XR. In such encodings, the most-significant 4 bits of each color channel are treated as providing additional "headroom" and "toe room" beyond the range of values that represents the nominal black-to-white signal range.
Moreover, 16-bit and 32-bit floating point color component codings are also supported in JPEG XR. In these cases the image is interpreted as floating point data, although the JPEG XR encoding and decoding steps are all performed using only integer operations (to simplify the compression processing).
The shared-exponent floating point color format known as RGBE (Radiance) is also supported, enabling more faithful storage of High Dynamic Range (HDR) images.
In addition to RGB and CMYK formats, JPEG XR also supports grayscale and multi-channel color encodings with an arbitrary number of channels.
A PhotoShop plugin was released:
http://news.cnet.com/8301-13580_3-9829967-39.html
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