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diff --git a/doc/cal_format.html b/doc/cal_format.html new file mode 100644 index 0000000..3e40205 --- /dev/null +++ b/doc/cal_format.html @@ -0,0 +1,216 @@ +<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> +<html> + <head> + <title>Calibration Format File (.cal)</title> + <meta http-equiv="content-type" content="text/html; + charset=ISO-8859-1"> + <meta name="author" content="Graeme Gill"> + </head> + <body> + <h2>Description of the .cal format</h2> + Device calibration information. This is ASCII text, <a + href="File_Formats.html#CGATS">CGATS</a>, Argyll specific format, + used + to hold a description of device setup information that brings it to + a + desired calibration state. Calibration files are created by <a + href="synthcal.html">synthcal</a>, <a href="dispcal.html">dispcal</a> + and <a href="printcal.html">printcal</a>.<br> + <br> + While fully compatible with the CGATS.5 Data Exchange Format, the + particular required keywords and fields are unique to Argyll, hence + an + Argyll specific file identifier <span style="font-weight: bold;">CAL</span> + is used to avoid confusion with standard ANSI or CGATS files.<br> + <br> + The <span style="font-weight: bold;">.cal</span> format changes + from + time to time with new releases, to add new functionality, but + generally + retains backwards compatibility. Note that in the description below, + the word "may" indicates an optional component, while the word + "shall" + indicates a necessary component.<br> + <br> + Generally a .cal file contains only one table, the table containing + the + setup information. <br> + <br> + <br> + The table contains the following:<br> + <br> + The file identifier (First 7 characters) shall be <span + style="font-weight: bold;">CAL</span>.<br> + <br> + A <span style="font-weight: bold;">#</span> character introduces a + comment.<br> + <br> + <span style="font-weight: bold;"><span style="font-weight: bold;"><span + style="font-weight: bold;"></span></span></span>There may be <span + style="font-weight: bold;">DESCRIPTOR</span>, <span + style="font-weight: bold;">ORIGINATOR</span>, or <span + style="font-weight: bold;">CREATED</span> keywords and values (as + per + CGATS).<br> + <br> + There shall be a <span style="font-weight: bold;">DEVICE_CLASS</span> + keyword that has a value of <span style="font-weight: bold;">"OUTPUT</span>", + "<span style="font-weight: bold;">DISPLAY</span>" or <span + style="font-weight: bold;">"INPUT"</span>.<br> + This indicates what type of device the calibration information is + suitable for.<br> + <br> + A <span style="font-weight: bold;">"DISPLAY"</span> type device may + have a <span style="font-weight: bold;">VIDEO_LUT_CALIBRATION_POSSIBLE + </span>keyword that + must have a value of "<span style="font-weight: bold;">NO</span>" or + "<span style="font-weight: bold;">YES</span>", to indicate whether + the display has the ability to be calibrated by loading VideoLUT + values.<br> + <br> + There shall be a keyword <span style="font-weight: bold;">COLOR_REP</span> + that has a value that indicates what colorspaces of the device + values. + The colorspaces shall be encoded with one or two letters + per + component. The device spaces shall use the + following letter encoding:<br> + <br> + <span style="font-weight: bold;"><span style="font-weight: bold;"></span></span> +Cyan + + + C<br> + Magenta + M<br> + Yellow + + Y<br> + Black + + K<br> + Orange + + O<br> + Red + + R<br> + Green + + G<br> + Blue + + B<br> + White + + W<br> + Light Cyan + + c<br> + Light +Magenta + m<br> + Light +Yellow + y<br> + Light +Black + k<br> + Medium Cyan + 2c<br> + Medium Magenta + + 2m<br> + Medium Yellow + 2y<br> + Medium Black + 2k<br> + Light Light Black 1k<br> + <br> + There may be an a prefix <span style="font-weight: bold;">i</span> + preceding the device space letter encoding, indicating that although + the space appears to be an additive space, it is in fact a + subtractive + device.<br> + <br> + Typical values might be: "<span style="font-weight: bold;">RGB</span><span + style="font-weight: bold;"></span>" for an RGB display, "<span + style="font-weight: bold;">iRGB</span><span style="font-weight: + bold;"></span>" + for an RGB printer, "<span style="font-weight: bold;">CMYK</span>" + for + a + printer, "<span style="font-weight: bold;">RGB"</span> for an RGB + scanner.<br> + <br> + The <span style="font-weight: bold;">NUMBER_OF_FIELDS</span> + keyword + shall have a value that indicates the number of fields in each data + set, e.g. <span style="font-weight: bold;">4</span> (as per CGATS).<br> + <br> + The start of the declaration of the fields shall be marked by the <span + style="font-weight: bold;">BEGIN_DATA_FORMAT</span> keyword (as + per + CGATS).<br> + <br> + The fields shall use the standard CGATS pattern of the full + colorspace + identified followed by the individual colorant identifier. There + shall + be an initial input index value identified by the letter <span + style="font-weight: bold;">I</span>.<br> + <br> + For an RGB device, the + following fields would be used:<br> + <br> + <span style="font-weight: bold;">RGB_I</span> + + The device value input value between 0.0 and 1.0.<br> + <span style="font-weight: bold;">RGB_R</span> + + The Red device value input value between 0.0 and 1.0.<br> + <span style="font-weight: bold;">RGB_G</span> + The Green device value input value between 0.0 + and + 1.0.<br> + <span style="font-weight: bold;">RGB_B</span> + The Blue device value input value between 0.0 + and + 1.0.<br> + <br> + The corresponding field names for a CMYK device would be <span + style="font-weight: bold;">CMYK_I</span>, <span + style="font-weight: bold;">CMYK_C</span>, <span + style="font-weight: bold;">CMYK_M</span>, <span + style="font-weight: bold;">CMYK_Y</span> and <span + style="font-weight: bold;">CMYK_K</span>, etc.<br> + <br> + The definition of the fields shall be terminated by the <span + style="font-weight: bold;">END_DATA_FORMAT</span> keyword (as per + CGATS).<br> + <br> + The <span style="font-weight: bold;">NUMBER_OF_SETS</span> keyword + shall have a value that indicates the number of sets of data, e.g. <span + style="font-weight: bold;">256</span> (as per CGATS).<br> + <br> + The start of the values of the data sets shall be marked by the <span + style="font-weight: bold;">BEGIN_DATA</span> keyword (as per + CGATS).<br> + <br> + Each set of data shall be on one line, and shall be separated by + white + space. All values shall be normalized to lie between 0.0 and 1.0.<br> + <br> + The end of the values of the data sets shall be marked by the <span + style="font-weight: bold;">END_DATA</span> keyword (as per CGATS).<br> + <br> + There may then be device type specific extra tables that hold target + or + device behavior information. These will be specific to the tool that + creates that particular type of calibration.<br> + <br> + Generally any other keywords and values will be ignored.<br> + <br> + <br> + </body> +</html> |