Reading a File

Contents:

How to Read a GR image

Typical functions that you would use to read general raster images are as follows:

Sample Program

The gr_rd program is a sample program for reading a GR image. You can either download the C or FORTRAN program at the end, or just take a look at the HTML version, with the HDF calls highlighted: If you have downloaded this program, then you can compile and run it. Following is a detailed review of what this program does: ADDITIONAL EXERCISES:
Change the stride to 2 (and edge accordingly). What happens?
Change the edge to read in a line at a time.

Output of Sample Program

The output of this program is as follows: 
Image Data:
Component 1:
  1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 
  2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 
  3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 
  4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 
  5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 
  6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 
  7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 
  8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 
  9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 
  10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 
  
Component 2:
  1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 
  2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 
  3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 
  4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 
  5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 
  6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 
  7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 
  8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 
  9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 
  10 11 12 13 14 15 16 17 18 19 20 21 22 23 24

Download Sample Program (optional)

Programs used in this tutorial: [Compiling a program]