Hi all,
I have just released an update with a new version of the DSLR_RAW module for all platforms: 1.3.2.313. This version adds new options to continue exploiting more features of the
DCRAW back end, written by Dave Coffin.
New FeaturesNo image cropMost (all?) digital cameras don't expose the entire sensor area. This means that what is normally downloaded from a digital camera is not the whole raw frame, but only the
picture area, which excludes several 'unused' regions of pixels. This has been also the case of PixInsight, until now. Version 1.3.2 of the DSLR_RAW module provides a new option, namely
no image crop, available on the RAW Format Preferences dialog.
When this option is enabled, the whole raw frames are loaded, including unexposed regions. In general, these regions are different for each camera brand and model. For example, the Canon EOS 5DS has two unexposed regions: one at the left side of the frame with 160 columns of pixels, and a second one with 64 rows at the top. The Nikon D3, on the other hand, has just two columns of two pixels each at the left and right sides of the frame. Note that these unexposed areas are not just image borders; they are real sensor pixels with their own signal and noise. In the case of all Canon cameras I've seen, at least, unexposed areas don't show any Bayer pattern, so they seem to be not covered by the CFA filter. I am sure that many users with much more direct experience with camera hardware will know more about this.
In my opinion, unexposed raw frame regions could be useful as overscan areas, at least for some camera models (Canon, mostly). Our preprocessing tool set fully supports multiple overscan regions, so this option directly opens a door for experimentation. At the very least, it provides us with more flexibility, which is one of the leitmotifs of PixInsight.
This option is always disabled by default. It can only be applied when loading raw, uninterpolated frames, so it is ignored when one of the interpolation options is selected.
No white balanceWhen this option is enabled, interpolated digital camera images will be loaded without any white balance scaling applied. By default, when this option is not selected, and none of the other white balance options is selected either (namely,
automatic and
camera white balance), DCRAW applies a default set of camera-dependent
daylight multipliers. For informative purposes, the values of these multipliers are always written to the console when you load a digital camera image, along with other important metadata items such as frame dimensions, CFA patterns, color spaces, etc.
With this option enabled, the DSLR_RAW module behaves just as the Debayer tool, that is, the raw pixels are loaded and interpolated as they are stored in the device, without any additional white balancing transformation. Note however, that DCRAW always rescales interpolated images, which Debayer does not.
This option is disabled by default. Obviously, its value is always ignored when raw CFA data are loaded (including the superpixel mode and both single-plane monochrome and RGB CFA options).
New Format HintsThis version also implements new format hints to provide access to the new options. For reference, this is the complete list of the input format hints available in the new version of the DSLR_RAW module:
rawSelects a set of options to load pure raw data as an RGB color image.
previewSelects a set of options to load a de-Bayered RGB image with half-size interpolation.
bilinearSelects bilinear interpolation for de-Bayering.
fastA synonym for "bilinear".
vngSelects VNG interpolation.
ppgSelects PPG interpolation.
ahdSelects AHD interpolation.
half-sizeSelects fast half-size interpolation (intended for previewing images).
interpolate-as-4-colorsEnables the
interpolate RGB as four colors option.
no-interpolate-as-4-colorsDisables the
interpolate RGB as four colors option.
auto-white-balanceEnables the
automatic white balance option.
no-auto-white-balanceDisables the
automatic white balance option.
camera-white-balanceEnables the
camera white balance option.
no-camera-white-balanceDisables the
camera white balance option.
no-white-balanceEnables the
no white balance option (hence, disables white balancing for interpolated images).
daylight-white-balanceDisables all white balancing options. Enables dcraw's daylight multipliers.
super-pixelsEnables the
create super-pixels option. Implicitly disables the
create raw Bayer RGB image and
create raw Bayer CFA image options.
no-super-pixelsDisables the
create super-pixels option.
bayer-drizzleEnables the
create raw Bayer RGB image option. Implicitly disables the
create super-pixels and
create raw Bayer CFA image options.
no-bayer-drizzleDisables the
create raw Bayer RGB image option.
cfaEnables the
create raw Bayer CFA image option. Implicitly disables the
create super-pixels and
create raw Bayer RGB image options.
no-cfaDisables the
create raw Bayer CFA image option.
auto-flipDisables the
no image flip option.
no-auto-flipEnables the
no image flip option.
auto-cropEnables automatic crop of unexposed frame regions (always enabled by default).
no-auto-cropDisables automatic crop of unexposed frame regions.
black-point-correctionDisables the
no black point correction option.
no-black-point-correctionEnables the
no black point correction option.
clip-highlightsDisables the
no highlights clipping option.
no-clip-highlightsEnables the
no highlights clipping option.
noise-threshold <n>Sets the
noise threshold parameter to the specified integer <n>. If <n> is zero, disables the wavelet noise reduction feature.
no-noise-reductionDisables wavelet noise reduction. Equivalent to "noise-threshold 0".
