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    Lumix pictures corrupted by Irfanview

    My new Lumix (Panasonic DMC-LX3) camera can take RAW images. The camera comes with software called Silkypix that can read and process the raw images, which btw have extension RW2.

    I was hoping Irfanview could read them (is there some plugin I don't know about?), but it cannot.

    When Irfanview encounters one of these RW2 files it thinks they are tiff files and prompts with a question window that says something like: tif file found with incorrect extension, do you want to fix it?. If you answer yes Irfanview changes the extension, but still cannot open the picture, because, of course it is not really a tif file. So I change the extension back to RW2 like it should be, but too my dismay, the file content (header info maybe) has also been changed and silkypix cannot open it anymore either.

    In effect, irfanview trashed the picture .. there seems to be no way to get it to open with anything after answering 'yes' to the irfanview prompt.

    Now, the picture was not very important, so mostly I just wanted to say that I think Irfanview should be modified so as not to mis-identify RW2 pictures as tiff, and not corrupt them.

    Also, is there any plugin available or in the offing to allow Irfanview to open RW2 files?

    Thanks for any help/comments/replies.

    --Jim

    #2
    Either that, or Panasonic should modify its RW2 format so that it doesn't identify itself as a TIF file in the header.

    I don't think IrfanView needs to support every possible RAW format. I think camera users should use the software provided with their camera for editing RAW images, or a specialised photo-editor.

    IrvanView is just an image viewer. The plugin supports some common RAW formats: CRW CR2 DNG NEF RAF ORF MRW ERF DCR SRF X3F PEF EFF
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      #3
      Originally posted by Bhikkhu Pesala View Post
      Either that, or Panasonic should modify its RW2 format so that it doesn't identify itself as a TIF file in the header.

      I don't think IrfanView needs to support every possible RAW format. I think camera users should use the software provided with their camera for editing RAW images, or a specialised photo-editor.

      IrvanView is just an image viewer. The plugin supports some common RAW formats: CRW CR2 DNG NEF RAF ORF MRW ERF DCR SRF X3F PEF EFF
      Thanks for the quick reply. Basically I agree that specialized software (or the camera) should process raw files.

      However, are you sure that Panasonic does identify its raw files as TIF? Here is a link to the first 300 hex bytes of a Panasonic raw file. I see "Panasonic DMC LX3" in the file but I don't see anything about TIF.



      --Jim

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        #4
        Apparently there are some bytes in the file that IrfanView is picking up that identifies them as TIF, unless it is just guessing, which seems improbable.

        Whatever, I don't see it as Irfan's duty to fix IrfanView to correctly identify every proprietary file type that was ever invented.

        The program does warn the user before making any change to the file. If the user knows its not a TIF file, then he/she should decline the offer to rename the file extension to TIF.
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          #5
          Originally posted by Bhikkhu Pesala View Post
          Apparently there are some bytes in the file that IrfanView is picking up that identifies them as TIF, unless it is just guessing, which seems improbable.

          Whatever, I don't see it as Irfan's duty to fix IrfanView to correctly identify every proprietary file type that was ever invented.

          The program does warn the user before making any change to the file. If the user knows its not a TIF file, then he/she should decline the offer to rename the file extension to TIF.
          Irfanview says quite positively that it has found a TIF file with incorrect extension and asks the user if it should rename the file. That is misleading to the user. The user who believes Irfanview will have their file permanently corrupted. Changing the name back will NOT fix it. That is NOT how Irfanview should behave.

          Irfanview should tell the user it has found a file that appears to be a TIF file and that it can rename the file and change the header. It should warn the user that this MAY render the file unreadable by irfanview as well as by any other software.

          Of course Irfanview should not be expected to identify all proprietary file types. But if it cannot correctly identify a TIF file, I would rather it not say anything. And if it is going to do something more than change the file name, then it should say so.

          --Jim

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            #6
            Originally posted by jbuddenh View Post
            And if it is going to do something more than change the file name, then it should say so.
            IMO that is the real crux of this matter.

            IrfanView presents the user with an option that clearly states that only a filename will be changed, which the user knows is easy to change back if unmotivated.

            But in fact IrfanView also modifies the content of the file, without first warning the user, or even informing him afterwards that such a change was made.

            That is unacceptable, as files should never be altered without informing the user (except after giving a command specifically intended for alterations). And preferably this should be done as a warning before the user has to confirm the file change...

            I agree with Bhikku that it would be absurd to demand that IrfanView support every existing format, but regardless of formats supported the program should always be truthful about changes made, and never call a change of file content as well as its name only by the term "rename".

            Btw: This could be a translation issue. I wonder what that message says in other languages, and especially in the original German.

            Either way, as long as that message can be found in the translation database, it should be possible to change the text without requiring any work by Irfan himself, in the same way as new translations are made.
            (I assume that he is not that multi-lingual himself... )

            Best regards: dlanor

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              #7
              I tried the same experiment with an *.orf RAW file. It opens OK in IrfanView. If I rename it to TIF I get a decode error that is an invalid TIF file. I name it back to ORF and it opens fine, just as before.
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                #8
                Originally posted by Bhikkhu Pesala View Post
                I tried the same experiment with an *.orf RAW file. It opens OK in IrfanView. If I rename it to TIF I get a decode error that is an invalid TIF file. I name it back to ORF and it opens fine, just as before.
                This clearly means that for your test file no file content was changed, which is of course a good thing. But it proves nothing in regard to files of other types with other content.

                And jbuddenh also described trying to change the extension of his files back to RW2 again, but in his case that did not help, which still indicates that some content was changed.

                Personally I have no 'stake' in this myself, except that I want it clarified whether or not IrfanView can ever change file content without telling the user, because if it can do so I consider that a horrible bug...

                I suggest that jbuddenh attach some of his picture files that give this problem here (or elsewhere with just links placed here), so that you Bhikku and other site members get a chance to try this out. Regardless of what the real truth is here, we do need to know it for certain.

                Best regards: dlanor

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                  #9
                  IrfanView doesn't claim to be able to read RW2 RAW files, which is a new proprietary format. If a user tries to do something with IrfanView that it was never designed to do, and doesn't claim to do, then they should exercise special caution. Since the user knows very well that it is not a TIF file, then the user should not accept the offer to rename it.
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                    #10
                    @jbuddenh: can you provide a RW2 file of yours, so we can experiment if and how IV changes it?
                    IrfanPaint developer
                    The latest stable IrfanPaint version is the 0.4.13.70.
                    IrfanPaint is now open-source (released under BSD license).

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                      #11
                      The file in the screenshot does actually - almost - identify itself as a TIFF: The first two bytes are 49 49 but the following two bytes (55 00) should have been 2A 00 if it was indeed a TIFF file.
                      What seems to happen, then, is that IrfanView only looks at the first two bytes and assumes it's a TIFF - which is of course both lazy and wrong.

                      From Wikipedia:
                      Every TIFF begins with a 2-byte indicator of byte order: "II" for little endian and "MM" for big endian byte ordering. The next 2 bytes represent the number 42, selected "for its deep philosophical significance". The 42-reading depends upon the byte order indicated by the 2-byte indicator.

                      Format Description for TIFF_6 -- A tag-based file format for storing and interchanging raster images. TIFF serves as a wrapper for different bitstream encodings for bit-mapped (raster) images. The different encodings may represent different compression schemes and different schemes for color representation (photometric interpretation).


                      The easy way to find out if the file has been changed is to install WinMerge and compare it with the original. If the files are identical it will tell you so, otherwise it will show what has been changed.
                      WinMerge is an Open Source differencing and merging tool for Windows. WinMerge can compare both folders and files, presenting differences in a visual text format that is easy to understand and handle.

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