Is there a way to extract text information from a postscript file? (.ps .eps)
It's likely that pgplot drew the fonts in  the text directly with lines rather than using text. Especially since pgplot is designed to output to a huge range of devices including plotters where you would have to do this.
Edit:
If you have enough plots to be worth
    the effort than it's a very simple
    image processing task. Convert each
    page to something like tiff, in mono
    chrome Threshold the image to binary, 
    the text will be max pixel value. 
Use a template matching technique.
    If you have a limited set of
    possible labels then just match the
    entire label, you can even start
    with a template of the correct size
    and rotation. Then just flag each
    plot as containing label[1-n], no
    need to read the actual text. 
If you
    don't know the label then you can
    still do OCR fairly easily, just
    extract the region around the axis,
    rotate it for the vertical - and use
    Google's free OCR lib
If you have pgplot you can even
    build the training set for OCR or
    the template images directly rather
    than having to harvest them from the
    image list
I want to extract the text information contained in a postscript image file (the captions to my axis labels).
These images were generated with pgplot. I have tried ps2ascii and ps2txt on Ubuntu but they didn't produce any useful results. Does anyone know of another method?
Thanks