X-Git-Url: https://cads.iiap.res.in/gitview/?p=fits2jpeg.git;a=blobdiff_plain;f=README.txt;h=eeace2087ad42da83bf075e7a26fa8459dce4092;hp=2164ec039cacfe1a77ed3dc3100c2b4ef886a988;hb=43cf6bddbf02b21c68b405e267605b1b64cddd8d;hpb=e9b7faa7d8a84a6a7f0e1b65c8859b7405568890 diff --git a/README.txt b/README.txt index 2164ec0..eeace20 100644 --- a/README.txt +++ b/README.txt @@ -6,12 +6,11 @@ README file for CADS/UVS fits2jpeg software 0. FEATURES ----------- -fits2jpeg is a tiny program to read FITS Images and convert them -to jpeg, which is more popular. This software supports various -type of intensity scaling and image enhancements. fits2jpeg do not -support coordinate axes overlay. fits2jpeg supports batch mode -operations - for instance, converting several fits files to jpeg -at once. +fits2jpeg is a tiny program to read FITS Images and convert them to jpeg, which +is more popular. This software supports various type of intensity scaling and +image enhancements. fits2jpeg do not support coordinate axes overlay. fits2jpeg +supports batch mode operations - for instance, converting several fits files to +jpeg at once. 1. BUILD/INSTALL @@ -26,9 +25,10 @@ Pre-requisites: http://heasarc.gsfc.nasa.gov/docs/software/fitsio/fitsio.html b) JPEGLIB - jpeg library and headers. libjpeg is installed by default on most - platforms, but we need the header files too. Once you have cfitsio - and jpeglib installed, you may proceed with compiling jpeg2fits. + jpeg library and headers. libjpeg is installed by default on most platforms, + but we need the header files too. Once you have cfitsio and jpeglib + installed, you may proceed with compiling jpeg2fits. + Follow these 4 steps: @@ -61,45 +61,74 @@ Pre-requisites: 2. Type `make' to compile the package. 3. Type `make install' to install the programs and any data files and - documentation. By default, the binary is copied to /usr/local/bin. - You may change this destination by passing on the following - argument to configure: + documentation. By default, the binary is copied to /usr/local/bin. You may + change this destination by passing on the following argument to configure: --prefix=/your/chosen/destination Which would result in the binary in /your/chosen/destination/bin You may need to ensure that in $PATH to run the program. - 4. You can remove the program binaries and object files from the - source code directory by typing `make clean'. + 4. You can remove the program binaries and object files from the source code + directory by typing `make clean'. -You may read more about configure script and others in the accompanying -file named `INSTALL.txt'. +You may read more about configure script and others in the accompanying file +named `INSTALL.txt'. 2.USAGE ------- - fits2jpeg [options] + Usage: fits2jpeg [options] + You need to specify a fits image file for this program to + work. Everything else is optional. A brief description of them are + listed below: - Options are: -h help + Prints out a usage-help message, much like this section. -s - scale for output image intensity. Valid arguments are: - - linear for linear scaling, default + scale for output image, where can be: + linear Linear scale, default sqroot for square root scale square for quadratic scale cubic for cubic scale log for log scale - - -e - Imaghe enhancement operations. Valid arguments are: - - equalize perform histogram equalization - normalize perform a linear contrast stretch - (use cutoffs at 1% and 99% for image data) + normalize for linear histogram stretch + equalize for histogram equalization + + -n + Negate the image + + -q + quality factor. Defines the jpeg encoding quality + Valid range: 0-100, default value: 100, which means + best quality and largest file-size. + + -d + Write jpeg file to this specified directory. Will + create it if needed. Default is to write jpeg in the + same directory of fits image file + + -r : + Clip output image to min-max range. Eg: + 0:100 Use only values in the range 0-100 + 100:0 Same as above, but negative image + :10 Clip everything above 10 + 10: Clip everything below 10 + + -z + Resize/Scale output image by . Eg: + 0.5 Shrink output to half of input + 2.0 Magnify output to double the size + Allowed range: 0.01 to 4.0 + NOTE: Zooming will be carried out after all other + operations, before writing out jpeg image + + fits2jpeg uses a bilinear interpolation based algorithm + to scale the image. Allowed range: 0.01 to 4.0 + NOTE: Anything outside the allowed range will be clipped + to this range. Output will be written to .jpg. For eg., @@ -107,32 +136,55 @@ file named `INSTALL.txt'. writes output to jpeg file 30dor.jpg - Wild card entries allowed in . For eg: *.fits, - m31*.fits ngc???.fits etc. + Wild card entries allowed in . For eg: *.fits, m31*.fits + ngc???.fits etc. - More examples: - i. fits2jpeg -s cubic sirius.fits +3.1 Examples: +------------- + i. fits2jpeg -s log sirius.fits + will write out sirius.jpg, flux/intensity in log scale ii. fits2jpeg -s sqroot *.fits - Converts all fits files in the directory to jpegs, with - square-root scaling of flux/intensity - Good for very - high dynamic range images -iii. fits2jpeg -e normalize ngc4151.fits - Converts ngc4151.fits to ngc4151.jpg, contrast stretched. + Converts all fits files in the directory to jpegs, with square-root scaling + of flux/intensity - Good for very high dynamic range images + +iii. fits2jpeg -n ngc4151.fits + + Converts ngc4151.fits to ngc4151.jpg, negative image. -NOTE: You can perform scaling + enhancing on an image. Scaling will - always be performed first. In most cases combining these two - would lead to un-usable images :) + iv. fits2jpeg -s square -n -r 10:2000 m31.fits + + Write out m31.jpg, after square scaling of flux/intensity, negate image and + clip pixel values in the range 10 to 2000 units. + + v. fits2jpeg -s equalize -r 200: -d/path/to/mydir NGS253*.fits + + Reads all fits files in the present directory that matches the filename + patterm, performs a histogram equalization, drops pixel values below 200 + and write out all the corresponding jpeg files to directory /path/to/mydir + Will create the destination directory tree if it does not exist. + + +3.1. Sequence of operations +--------------------------- +Here is the sequence of operations, after reading the fits file: + + i. clip the image to user specified pixel limits, if it was requested + ii. Squeeze image pixel values to jpeg limits (0 - 255) + iii. image scaling function, default being linear pixel scale + iv. Negate the image, if requested + v. Image zoom - magnify or shrink the image + vi. Write out jpeg file 3. DOCUMENTATION ---------------- -An extensive coverage of how this program works along with line -by line account of the happenings within the code, are dealt with -in the user manual, which is yet to be written :( +An extensive coverage of how this program works along with line by line account +of the happenings within the code, are dealt with in the user manual, which is +yet to be written :( 4. LICENSE: GPL [See the file COPYING.txt for details] @@ -141,10 +193,9 @@ in the user manual, which is yet to be written :( 5. DISCLAIMER ------------- -You may encounter bugs in this software. If you do, please -report them. Your bug reports are valuable contributions, -since they allow us to notice and fix problems on -machines/platforms we don't have, and/or remained un-noticed. +You may encounter bugs in this software. If you do, please report them. Your bug +reports are valuable contributions, since they allow us to notice and fix +problems on machines/platforms we don't have, and/or remained un-noticed. 6. REPORTING BUGS @@ -157,6 +208,7 @@ If you are too lazy, drop in an email to: cads_AT_iiap.res.in Either way, please include as many details as possible. + ----------------------------------------------------------- Reks, 28 June 2012 - Last modified: 28 June 2012 + Last modified: 10 July 2012