Sd_rfmt reformats images compressed with the old JPEGLSD and WSQ14 compression, on NIST Special Databases 4, 9, 10, 18 (JPEGLSD) and 14 (WSQ14), so the images can be decompressed with the new commands djpegl and dwsq.
When JPEGLSD was used to compress images on NIST Special Databases (4, 9, 10, 18) the NIST IHEAD header was used to store the data for the JPEGLSD compression. In the new versions cjpegl and djpegl the full JPEG format is used not the IHEAD header.
The WSQ14 compression used on SD14 has problems with ordering of the data in the compressed file. Sd_rfmt simply reorders the data to comply with the format specified in the FBI's Criminal Justice Information Services (CJIS) document, "WSQ Gray-scale Fingerprint Compressions Specification," Dec. 1997. This is the only fingerprint compression format accepted by the FBI IAFIS system. NOTE: The method for selecting the quantization amount was refined after the release of SD14 so the data loss in the reconstructed image may be more than seen when using the new versions cwsq and dwsq.
Specify that the input image is from NIST Special Database #.
the extension of the reformatted output file. ªTo construct the output filename, sd_rfmt takes the input filename and replaces its extension with the one specified here.
the compressed input file to be reformatted.
From test/imgtools/execs/sd_rfmt/sd_rfmt.src:
% sd_rfmt 7 jpl sd09.old % sd_rfmt 10 jpl sd10.old % sd_rfmt 14 wsq sd14.old % sd_rfmt 18 jpl sd18.old Convert the special database images to the correct formatted compressed files (JPEGL and WSQ). User could use rdjpgcom and rdwsqcom to read the NISTCOM comment that is written in the reformatted output file. After reformatting the new file can be decompressed with djpegl or dwsq.