Changes between Version 3 and Version 4 of examples

Timestamp:

Dec 3, 2010, 2:21:00 PM (14 years ago)

Author:

bpt

Comment:

--

examples

@@ -17 +17 @@
 The colour calibration assumes that you have a colour chart located in approximately the same place in each image.  Select the colour chart using the rectangle in the delineator window (View -> Display rectangle, then click and drag).  The box should be a reasonably tight fit to the chart.  When you select colour calibrate, the algorithm samples circles regularly spaced on a 4 (wide) by 6 (high) grid, and iteratively tries to segment pixels of each colour and align the grid to the segmented colour patches.  This seems to improve the alignment (e.g. for small rotations).  The mean colours from each patch are then compared with the known colours to build a non-linear model of the colour mapping and apply it to the image.  In batch mode you are given the option to use the calibration from the first image for all images, or to update the sampled colours (by estimating the grid position, scale and orientation) for each image.
 
-The known colours are supplied in a file, starting with the whitepoint for the measured values (e.g. 65 for the d65 illuminant), followed by each patches colour.  The colours are ordered from top to bottom and left to right.  An example is given below, in this example the first 6 values represent the grey values from white to black, which is the column on the (viewers) left of the chart.
+The known colours are supplied in a file, starting with the whitepoint for the measured values (e.g. 65 for the d65 illuminant), followed by each patches colour (in L*a*b* space).  The colours are ordered from top to bottom and left to right.  An example is given below, in this example the first 6 values represent the grey values from white to black, which is the column on the (viewers) left of the chart.
 
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