-
SIDIMG: Importing the MrSID raster format to IMG or JPEG
Presentation and options
The MrSID files are highly compressed raster files thanks to the use of wavelet transforms. MrSID typically uses lossy compression (also called non-conservative, degrading, or lossy) (like the JPEG format) and, therefore, the quality is inferior (perhaps imperceptibly) in relation to the data from which it was generated. As a counterpart, it is the type of compression that most strongly compresses an image; In spite of this non-conservative character, the images usually have a visual appearance very similar to the original ones, unless they have been generated with extremely high compression levels; This is an important difference in relation to the conventional JPEG format, which begins to present visual artifacts at lower compression levels. On the other hand, the MrSID format can also be efficiently compress and even without degrading the values of the original image (lossless, conservative, or lossless compression) although in this case the compression levels are not as high.
This application allows to obtain the information of the internal metadata of the MrSID format, import a MrSID to a JPEG format (grey or RGB, depending on the MrSID file) or extract between one and three IMG bands from a MrSID.
When MrSID images have been compressed without loss, it may make sense to recover the images as IMG files for analysis, although this implies that the files can occupy much more disk space than the original images.
In the case of importing to JPEG files, the conversion may become impossible if in this format the converted image occupies more than 2 Gbyte.
This application has the following options:
Show metadata:
Shows the internal metadata stored inside the MrSID file.
JPEG:
Generates a JPEG file from a MrSID image.
IMG:
Generates one IMG file from a greyscale MrSID file.
MULTIBANDA:
Generates three IMG files from a 24-bit MrSID file.
Syntax
Syntax:
- SIDIMG 0 MrSIDFileName
- SIDIMG 1 MrSIDFileName JPEGFileName [/QUALITAT] [/FWORLD]
- SIDIMG 2 MrSIDFileName IMGFileName
- SIDIMG 3 MrSIDFileName IMGFileName_R IMGFileName_G IMGFileName_B
Options:
- 0:
Shows the internal metadata stored inside the MrSID file.
- 1:
Generates a JPEG file from a MrSID image.
- 2:
Generates one IMG file from a greyscale MrSID file.
- 3:
Generates three IMG files from a 24-bit MrSID file.
Parameters:
- MrSIDFileName
(MrSID file name -
Input parameter): It is the name of the MrSID v2 or v3 file to be converted.
- JPEGFileName
(JPEG file name -
Output parameter): It is the name of the JPEG file resulting from the conversion.
- IMGFileName
(IMG file name -
Output parameter): It is the name of the IMG file resulting from the conversion for single-band (greyscale) MrSID.
- IMGFileName_R
(Red IMG file name -
Output parameter): It is the name of the IMG file resulting from the conversion of the red band of the RGB triplet.
- IMGFileName_G
(Green IMG file name -
Output parameter): It is the name of the IMG file resulting from the conversion of the green band of the RGB triplet.
- IMGFileName_B
(Blue IMG file name -
Output parameter): It is the name of the IMG file resulting from the conversion of the blue band of the RGB triplet.
Modifiers:
/QUALITAT=
(Compression quality)
Compression quality in a range [0,100], where [5,95] is the useful range although in many cases it is advisable to enter a value between 70 and 75 (default is 75). Low values indicate very low quality but high compression. (Input parameter) /FWORLD
(WORLD file)
Allows generating a world file (georeferencing) with the indicated extension. You can specify /FWORLD to generate it using the default extension. (Input parameter)