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  1. #11
    Mustafa Umut Sarac's Avatar
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    I had been recorded many images but they were wide angle forest and city pictures.
    I dont know this image has told quality but let me post it , this image comes from same family but its too dark.

    Umut

  2. #12
    Photo Engineer's Avatar
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    Quote Originally Posted by Mustafa Umut Sarac View Post
    Thank you Photo Engineer , Autochrome uses RGB and when it is scanned , it makes flat histogram.
    But when thinking ,
    What about digital cameras , they use RGB pixels and by this way , they should aim to give flat histograms but this is not true.

    Which is false ?

    Best,

    Umut
    When scanned, digital data is sending the fact that it is RGB. Analog data is sending the fact that it is CMY (K). I think that the information transmitted may be critical.

    PE

  3. #13

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    The histogram(s) of that image aren't flat when i look at it/them.
    Attached Thumbnails Attached Thumbnails Autochrome.jpg  

  4. #14
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    Hang on - what are you (we, possibly) attempting to compare here ?

    The histogram from one digital representation of a scanned image to a digital camera originated image of what I'm assuming is another another scene ??
    Cleared the bowel problem, working on the consonants...

  5. #15
    Mustafa Umut Sarac's Avatar
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    yes , histogram of this image is not flat but the lost ones had have . I will try to find at net again
    This is not new invention least 3 months old.

  6. #16

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    Quote Originally Posted by nick mulder View Post
    Hang on - what are you (we, possibly) attempting to compare here ?

    The histogram from one digital representation of a scanned image to a digital camera originated image of what I'm assuming is another another scene ??
    I think we are trying to figure out whether being an Autochrome does something special to the distribution of tones.

    One thing to establish before we start thinking about that is indeed whether there is something special about that, i.e. whether histograms of representations of Autochromes indeed would/could differ from histograms of represenations of other images.
    If so, there is a possibility that such a difference could (!) be due to the nature of Autochromes. If not, there's nothing to think about.

  7. #17

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    Quote Originally Posted by Mustafa Umut Sarac View Post
    yes , histogram of this image is not flat but the lost ones had have . I will try to find at net again
    This is not new invention least 3 months old.
    I have been looking on the net too, and as yet have not come across an Autochrome that has a flat line histogram.

  8. #18
    Mustafa Umut Sarac's Avatar
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    I am sure whatever I saw but not a proof at hand at this moment.
    I think We can reverse engineer the situation. What is the meaning of flat histogram , what kind of a image have a flat histogram. I am an Crossfield 656 Drum Scanner operator , have been printed 100 000 color negatives and been a service man for Heidelberg Newspaper machines , used many Leitz products and a thinker on classical paintings and the Leica relation for 15 years.

  9. #19

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    Flat histograms indicate that each tone in the range that the image could contain occurs equally often as any other tone.
    A continuous wedge would give such a tone frequency distribution.
    Or a scene in which the tones are distributed in another pattern (preferably one that represents a thing in real life), yet by some magic all appear as often as any other tone. Could happen though. But repeatedly, in different images of different scenes???

    Add in colour and consider that to have a flat line overall histogram, the histograms of all colour channels involved would also need to be flat, and it becomes even more difficult to imagine.

  10. #20
    Mustafa Umut Sarac's Avatar
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    QC , Lets continiue to reverse engineering. May be We can post process an image as you told and see the result. This is called histogram matching or something similar to it .
    Is there anyone who knows how to create such a histogram on a image or do I need to ask to hybrid photo ? This is not digital photography but get help from a calculator.

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