batch tiff to jpeg conversion script

Discussion in 'Python' started by rtilley@vt.edu, Jan 11, 2006.

  1. Guest

    Hope it's not inappropriate to post this here.

    Could someone critique my code? I have no Python programmers in my
    office to show this to. The script works OK, but should I do it
    differently? I especially don't like how I check to see if jpegs exist.

    The style may not be acceptable to some, but I'm concerned with
    substance, not style. Is there a 'more appropriate' way to do this?

    Thanks to all who take the time to give advice!

    -----------------------------------------------------------------
    import os
    import os.path
    #From PIL
    import Image

    def tiff_to_jpeg(path):

    for root, dirs, files in os.walk(path):
    for f in files:
    if os.path.splitext(os.path.join(root,f))[1].lower() ==
    ".tif":

    # If a jpeg is already present. Don't do anything.
    if
    os.path.isfile(os.path.splitext(os.path.join(root,f))[0] + ".jpg"):
    print "A jpeg file already exists for %s" %f

    # If a jpeg is *NOT* present, create one from the tiff.
    else:
    outfile = os.path.splitext(os.path.join(root,f))[0]
    + ".jpg"
    try:
    im = Image.open(os.path.join(root,f))
    print "Generating jpeg for %s" %f
    im.thumbnail(im.size)
    im.save(outfile, "JPEG", quality=100)
    except Exception, e:
    print e

    # Run Program
    path = '.'
    tiff_to_jpeg(path)
    , Jan 11, 2006
    #1
    1. Advertising

  2. Larry Bates Guest

    wrote:
    > Hope it's not inappropriate to post this here.
    >
    > Could someone critique my code? I have no Python programmers in my
    > office to show this to. The script works OK, but should I do it
    > differently? I especially don't like how I check to see if jpegs exist.
    >
    > The style may not be acceptable to some, but I'm concerned with
    > substance, not style. Is there a 'more appropriate' way to do this?
    >
    > Thanks to all who take the time to give advice!
    >
    > -----------------------------------------------------------------
    > import os
    > import os.path
    > #From PIL
    > import Image
    >
    > def tiff_to_jpeg(path):
    >
    > for root, dirs, files in os.walk(path):
    > for f in files:
    > if os.path.splitext(os.path.join(root,f))[1].lower() ==
    > ".tif":
    >
    > # If a jpeg is already present. Don't do anything.
    > if
    > os.path.isfile(os.path.splitext(os.path.join(root,f))[0] + ".jpg"):
    > print "A jpeg file already exists for %s" %f
    >
    > # If a jpeg is *NOT* present, create one from the tiff.
    > else:
    > outfile = os.path.splitext(os.path.join(root,f))[0]
    > + ".jpg"
    > try:
    > im = Image.open(os.path.join(root,f))
    > print "Generating jpeg for %s" %f
    > im.thumbnail(im.size)
    > im.save(outfile, "JPEG", quality=100)
    > except Exception, e:
    > print e
    >
    > # Run Program
    > path = '.'
    > tiff_to_jpeg(path)
    >

    The methodology seems just fine. You may (or may not) find
    the following code easier to read (not tested):

    for f in [file for file in files if file.lower().endswith('.tif')]:
    # If a jpeg is already present. Don't do anything.
    filename, extension=f.split('.')
    jpgfile="%s.jpg" % filename
    jpgpath=os.path.join(root, jpgfile)
    # If a jpeg is *NOT* present, create one from the tiff.
    if not os.path.isfile(jpgpath):
    try:
    im = Image.open(os.path.join(root,f))
    print "Generating jpeg for %s" % f
    im.thumbnail(im.size)
    im.save(jpgpath, "JPEG", quality=100)
    except Exception, e:
    print e

    continue

    print "A jpeg file already exists for %s" % f


    This code:

    1) only processess .tif files
    2) simplifies things by eliminating the splitext methods and
    slicing operations.
    3) eliminates else branch

    -Larry Bates
    Larry Bates, Jan 11, 2006
    #2
    1. Advertising

  3. Peter Hansen Guest

    wrote:
    > Hope it's not inappropriate to post this here.
    >
    > Could someone critique my code?

    [snip]
    > im.save(outfile, "JPEG", quality=100)


    From an effbot posting on 13 Jul 2002:

    '''JPEG quality 100 is overkill, btw -- it completely disables JPEG's
    quantization stage, and "mainly of interest for experimental pur-
    poses", according to the JPEG library documentation, which
    continues:

    "Quality values above about 95 are NOT recommended for
    normal use; the compressed file size goes up dramatically
    for hardly any gain in output image quality."

    (full text below):

    Should probably add something about this to the PIL docs...
    '''

    (As near as I can tell, so far, the last comment hasn't been followed
    through on.)

    -Peter
    Peter Hansen, Jan 11, 2006
    #3
  4. Guest

    Hi Peter. The guy who takes the pictures uses Photoshop to convert
    tiffs to jpegs one by one. When he does a 'Maxium Quality' conversion
    in Photoshop and I do a 100% quality conversion with Python and PIL,
    the two converted files are almost identical and this is what he
    wants... that's the only reason I'm using 100% quality. Thanks for the
    info!
    , Jan 11, 2006
    #4
  5. Guest

    Thanks for the example code Larry. It _is_ easier for me to read. I
    like the way you split the file on '.' I may use that. Thanks again!
    , Jan 11, 2006
    #5
  6. wrote:
    > Hi Peter. The guy who takes the pictures uses Photoshop to convert
    > tiffs to jpegs one by one. When he does a 'Maxium Quality' conversion
    > in Photoshop and I do a 100% quality conversion with Python and PIL,
    > the two converted files are almost identical and this is what he
    > wants... that's the only reason I'm using 100% quality. Thanks for the
    > info!


    Allow me interject two observations:

    1) You should tell the guy using Photoshop what Peter pointed out
    regarding the Jpeg Quality setting.

    2) Although it wouldn't be as flexible as your Python script, it's
    completely possible and fairly easy to automate such a conversion
    within Photoshop using 'Actions', which are like recorded macros,
    coupled with the Automate | Batch... submenu.

    Best,
    -Martin
    Martin Miller, Jan 11, 2006
    #6
  7. Peter Hansen Guest

    wrote:
    > Thanks for the example code Larry. It _is_ easier for me to read. I
    > like the way you split the file on '.' I may use that. Thanks again!


    Warning: that will fail on names with more than one "." in them. It's
    generally best to use the provided tools for working with paths, in this
    case os.path.splitext() which will do the right thing in any case (even
    on names without extensions!).

    -Peter
    Peter Hansen, Jan 11, 2006
    #7
  8. Peter Hansen Guest

    Martin Miller wrote:
    > wrote:
    >
    >>Hi Peter. The guy who takes the pictures uses Photoshop to convert
    >>tiffs to jpegs one by one. When he does a 'Maxium Quality' conversion
    >>in Photoshop and I do a 100% quality conversion with Python and PIL,
    >>the two converted files are almost identical and this is what he
    >>wants... that's the only reason I'm using 100% quality. Thanks for the
    >>info!

    >
    >
    > Allow me interject two observations:
    >
    > 1) You should tell the guy using Photoshop what Peter pointed out
    > regarding the Jpeg Quality setting.


    Or consider using PNG files instead, which can do pretty decent lossless
    compression, which might be what the guy really wants to do. I haven't
    compared a 100% JPG with a PNG but it might be instructive.

    -Peter
    Peter Hansen, Jan 11, 2006
    #8
  9. On 11 Jan 2006 13:42:21 -0800, "" <>
    declaimed the following in comp.lang.python:

    > Hi Peter. The guy who takes the pictures uses Photoshop to convert
    > tiffs to jpegs one by one. When he does a 'Maxium Quality' conversion
    > in Photoshop and I do a 100% quality conversion with Python and PIL,


    Current versions of PhotoShop have a batch convert capability...
    Though it does take some gaming to get the options on the action/command
    to work as expected.
    --
    > ============================================================== <
    > | Wulfraed Dennis Lee Bieber KD6MOG <
    > | Bestiaria Support Staff <
    > ============================================================== <
    > Home Page: <http://www.dm.net/~wulfraed/> <
    > Overflow Page: <http://wlfraed.home.netcom.com/> <
    Dennis Lee Bieber, Jan 12, 2006
    #9
  10. Guest

    Just curious... is PhotoShop _really_ recursive? We have dozens of
    levels of sub-folders where the pics have been sorted and thousands of
    pics. That's one reason I used os.walk()
    , Jan 12, 2006
    #10
  11. wrote:
    > Just curious... is PhotoShop _really_ recursive? We have dozens of
    > levels of sub-folders where the pics have been sorted and thousands of
    > pics. That's one reason I used os.walk()


    Yes, in the sense that there is an "Include All Subfolders" option for
    batch operation source files that recursively locates input files.
    However, at least in the version I have (CS), there is no obvious way
    to get it to recreate the input folder hierarchy with a different root
    folder specified as the destination (all the output files get put in
    single folder specified) -- something that could be fairly easily
    accomplished using a Python script.

    Since in this case you are doing file *conversions*, the output files
    will have a different extension than the orginals, and can therefore
    exist in the same folders (assuming there's enough disk space). This
    makes it possible to record a "Save As" command in the Action which to
    simply save the converted image back into the same folder as the
    orginal in a different format, thus preserving the file & folder
    layout.

    Sorry, but I feel any more detail on the process would be getting way
    too off-topic for this newsgroup. Feel free to contact me directly if
    you would like to discuss in more detail how to do this sort of thing
    from within Photoshop.

    Best,
    -Martin
    Martin Miller, Jan 12, 2006
    #11
  12. William Park Guest

    <> wrote:
    > Hope it's not inappropriate to post this here.
    >
    > Could someone critique my code? I have no Python programmers in my
    > office to show this to. The script works OK, but should I do it
    > differently? I especially don't like how I check to see if jpegs exist.
    >
    > The style may not be acceptable to some, but I'm concerned with
    > substance, not style. Is there a 'more appropriate' way to do this?
    >
    > Thanks to all who take the time to give advice!


    At the risk of being flamed... Have you tried ImageMagick utilities.
    For example,
    man convert

    --
    William Park <>, Toronto, Canada
    ThinFlash: Linux thin-client on USB key (flash) drive
    http://home.eol.ca/~parkw/thinflash.html
    BashDiff: Super Bash shell
    http://freshmeat.net/projects/bashdiff/
    William Park, Jan 30, 2006
    #12
    1. Advertising

Want to reply to this thread or ask your own question?

It takes just 2 minutes to sign up (and it's free!). Just click the sign up button to choose a username and then you can ask your own questions on the forum.
Similar Threads
  1. Ather Ali Shaikh
    Replies:
    1
    Views:
    2,821
    ASP.Confused
    Jul 23, 2004
  2. surendra
    Replies:
    1
    Views:
    8,265
    dipakPardesi
    Jun 21, 2008
  3. usao

    JPEG/TIFF routines?

    usao, Feb 16, 2004, in forum: C Programming
    Replies:
    6
    Views:
    1,612
    Richard Bos
    Feb 17, 2004
  4. ifiaz
    Replies:
    1
    Views:
    894
    Martien Verbruggen
    Nov 19, 2003
Loading...

Share This Page