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Thread: `Save As` gives poor results

  1. #1

    Default `Save As` gives poor results

    Hi Folks,

    When I use the `copy` command in the file menu i get good results.
    But when I click on `Save As` the resulting saved picture has a washed-out appearance, although i have the quality setting at 93, which gives me a similar file size in the copy (using 100% makes no difference to the quality)
    I am trying to sort and file a lot of pictures and using F8 and then choosing the destination takes 3 times as long as just using the `Copy As` icon.
    Anyone know how I can get a decent copy using `copy as`?

    4400 dual core +XP Pro
    latest version of Irfan View installed today

  2. #2
    Moderator Bhikkhu Pesala's Avatar
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    Default

    I don't notice any washed out appearance when using save as at high quality, but I do notice that my files get a lot bigger — that will depend on what JPG quality setting was used to save the file last time.

    I don't see why Copy (F8) takes you any longer. Once you have set the save directory, you only need to click one of the numbers at the bottom of the dialogue. That's no slower than using Save as… OK

    You could also use the Thumbnail browser, and move or copy several selected files at once.

  3. #3
    Multiple User j7n's Avatar
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    If you copy a file there can be no difference in quality. Always use simple copy if you don't intend to edit the graphics file. Note that you will always lose quality by saving to JPEG, even at the lowest possible compression.

    Copying and encoding functions each have their own purpose!!

    If you notice "washed out" appearance of newly saved JPEG images, make sure that you have disabled color subsampling.

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    Advanced User matera's Avatar
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    There is some confusion in terms here. I know of no Copy as icon (toolbar button), only Save as or Copy (to clipboard). The Copy button puts the image on the clipboard, but not as a file.

    The F8 (or File menu) Copy to should not take longer than Save as because once you have selected several different destinations you only have to click the number buttons, instead of browsing for a folder each time. If you select multiple images to copy-to, it takes more time off. You can only save-as one at a time. With 14 possible destinations, it can't be too bad (reminds self to clear out some obsolete destinations lol)

  5. #5

    Default

    Hmmm maybe it`s down to `Save as` recompressing a file which has been compressed and opened , so the loss of quality is through repeated compression?
    Just copying a file means it`s only been compressed once...

    Though if you crop a picture etc you don`t have much choice in using `Save as`? or is there another way without using `save as`?

    Wow thats a considerable loss in quality, even when saving at 100% quality.
    don`t suppose there is a way i could upload a `before` and `after` image to show you guys what`s happening?


    I have ticked `Keep original EXIF data` `Keep original IPTC data` `Keep original JPG-Comment` and `Reset EXIF orientation tag` and now after J7N`s comment I have disabled colour subsampling.

    And sorry about confusion above, I meant `Save As` not `Copy as` throughout.

  6. #6
    Moderator Bhikkhu Pesala's Avatar
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    Default

    Click the Manage Attachments button.

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    Multiple User j7n's Avatar
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    JPEG can be cropped without re-encoding in blocks of 8 or 16 pixels.

    Tools:
    1. JPEGCrop, http://sylvana.net/jpegcrop/
    2. IrfanView with plugin installed

    Create a selection, then go to Options -> JPG Lossless Crop.

    JPEGCrop is easier to use, because you can preview the crop beforehand and decide whether to crop 8 pixels more or less.


    You have to understand what color subsampling actually does, instead of just disabling it because I told you so. That option is comparable to reducing the image by 50%. Only the color channels are affected (hence color subs.). Now if your sample has little color detail to start with, such as hi resolution amateur photos, this may go unnoticed. While on computer generated, or small images you will definitely see it.

  8. #8
    Professional User Skippybox's Avatar
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    Default Compromises

    Quote Originally Posted by Trophonius View Post
    I am trying to sort and file a lot of pictures and using F8 and then choosing the destination takes 3 times as long as just using the `Copy As` icon.
    Anyone know how I can get a decent copy using `copy as`?
    Quote Originally Posted by Trophonius View Post
    Hmmm maybe it`s down to `Save as` recompressing a file which has been compressed and opened , so the loss of quality is through repeated compression?
    Just copying a file means it`s only been compressed once...

    Though if you crop a picture etc you don`t have much choice in using `Save as`? or is there another way without using `save as`?
    Can you elaborate on what you are doing? Are you just trying to retain the original images in the original folders, and sorting those files to one or more other folders, with some type of theme? Are you just doing file maintenance? Are you cropping or editing all the files your copying, or just a select few? Are you only going to crop/edit these files the one time, or do you plan on editing them in the future again?

    I have ticked `Keep original EXIF data` `Keep original IPTC data` `Keep original JPG-Comment` and `Reset EXIF orientation tag` and now after J7N`s comment I have disabled colour subsampling.
    Are you just telling us your settings, or do you actually want to keep all this data?

    Sometimes you have to decide what is more important to you: quality or file size. You seem to favor quality, so why not choose a lossless format for your end result, if your editing. Otherwise, accept the compromise of quality, for the compact file size you desire. Depending on your use for the image, maybe you should maintain copies of the cropped image in two formats.

    What you really should do is not start with a JPG at all. It is really only desirable for the final output, after all editing is done. But, if you can't, then you should make sure you're starting with the least compressed image possible.

    These things won't save you time, but have you tried the RIOT plugin for quality comparisons, or maybe even resizing your image larger, before saving to JPG?

    For most purposes, low-compression should be fine, and usually is indiscernible.

  9. #9

    Default

    Thanks for those suggestions guys.
    Skippybox asked: Can you elaborate on what you are doing?
    Basically finally decided to revamp and make some sense of all my various pictures and various 35mm negatives and prints, some going back to black and white days. So I have bought a second-hand Epson V200 scanner on ebay and I will have a bunch of folders - family, kids, holidays etc etc with separate folders for the `good` ones and folders for the more junky stuff. Quite a few could do with a bit of cropping.
    The idea was to open pictures, crop if necessary and `save as` to various folders.
    After which i aim to learn how to manipulate the pictures - gamma etc.., when `save as` would be useful again.

    At the moment it looks like i will have to add another folder to my save options, a `need cropping` folder, then crop those with j7n suggested lossless JPEGcrop. Be simpler if I could overcome this wash-out problem with IrfanView `save as` though.

    I have put a pair of images up on Imageshack so you can see what I am talking about. Curiously the difference between the imageshack pics seems less than between the same two pics on my computer!
    perhaps they have automatic image cleanup or something .The bigger file is the `saved as` one. Actually you can see the difference even in these thumbnails:




    Bhikkhu Pesala - sorry I can`t find a Manage Attachments button. Probably wouldnt know what to do if i did :-(

    `What you really should do is not start with a JPG at all. It is really only desirable for the final output, after all editing is done...` Yes I am beginning to realise that... bit too late for a lot of jpegs tho... but I have a few hundred 35mm negatives and lots of prints to scan in and will do it that way for those.
    Last edited by Trophonius; 29.08.2008 at 10:59 PM.

  10. #10
    Multiple User j7n's Avatar
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    Default

    Whatever this is, it's not related to color subsampling (the original has it, but the bad copy does not). A histogram adjustment has been performed upon the modified image. I can only guess how you did it.

    Do you have gamma correction enabled in preferences?

    Preferences -> Viewing -> Apply gamma correction

    A value > 1 will cause an effect like this. Each time you open and save the image, it will progressively get lighter.

    If you install the JPEG plugin, you will be able to perfom lossless crop from withing IrfanView 4.20. I find it less straightforward, but perhaps it will on the contrary to you.

    Always use lossless crop, if that is the only edit you wish to perform. It's very important.

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