[Having trouble reading the .img file]

Hi kathrynbottrell and future readers,

 

I found a solution to my problem. I downloaded NASAView from https://pds.nasa.gov/tools/nasa-view.shtml. This lets you open the pds image and then export it as a jpg, pdf or other file extension types.

 

Unfortunately, I was unable to code my own working binary reader for any general pds image file.

 

Hopefully this helps,

Samuel

[Having trouble reading the .img file]

Susie,

 

Thank you so much! This is amazingly helpful. Two more questions: 

 

The last line of the ascii header is marked "END", correct? On the following line, there are some NUL then a long string that describes all the characteristics of the file and then some code that is unreadable (I assume the binary array.)

 

1. Does the image start on the unreadable code on that same line? If I skip to the next line, the image I get is incorrect.

2. When the binary array is read, does it read top left to bottom right (going across the top line of pixels first, and then the second, and so on)?

 

Samuel

[Having trouble reading the .img file]

Hello,

 

Currently I'm working on a data analysis project using images from the Mars Opportunity Rover Pancam. I'm having trouble reading the .img files. I know the ascii detachable string contains all the information necessary. I'm trying to write a script to extract intensity of each pixel and place it into an array.

Right now I'm thinking LINES is height, LINE_SAMPLES is width and SAMPLE_BITS is bit per pixel. The checksum for this specific image is 7231232, but if I use the dimensions given in the lines, line_samples and sample_bits I get 65536 (for 64 x 64 x 16). Here is the data from the header. Am I interpreting the dimensions wrong?

/* IMAGE DATA ELEMENTS */



OBJECT                           = IMAGE

  INTERCHANGE_FORMAT             = BINARY

  LINES                          = 64

  LINE_SAMPLES                   = 64

  SAMPLE_TYPE                    = MSB_INTEGER

  SAMPLE_BITS                    = 16

  BANDS                          = 1

  BAND_STORAGE_TYPE              = BAND_SEQUENTIAL

  CHECKSUM                       = 7231232

  FIRST_LINE                     = 1

  FIRST_LINE_SAMPLE              = 1

  INVALID_CONSTANT               = 4095

  MAXIMUM                        = 2508

  MEAN                           = 1765.437500000000

  MEDIAN                         = 1767.000

  MINIMUM                        = 801

  MISSING_CONSTANT               = 0

  SAMPLE_BIT_MASK                = 2#0000111111111111#

  STANDARD_DEVIATION             = 199.9281

END_OBJECT                       = IMAGE



/* IMAGE HEADER DATA ELEMENTS */



OBJECT                           = IMAGE_HEADER

  HEADER_TYPE                    = VICAR2

  INTERCHANGE_FORMAT             = ASCII

  BYTES                          = 12800

  ^DESCRIPTION                   = "VICAR2.TXT"

END_OBJECT                       = IMAGE_HEADER



END

Thank you, 
Samuel