how do i change a .bmp to .jpg?

Discussion in 'other software & services' started by helen321, Sep 15, 2004.

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  1. helen321

    helen321 Guest

    when i post a picture here at wilders i often have to change from a .bmp to a .jpg. i've tried changing the extension name e.g picture.bmp to picture.jpg, it does seem to work, however when i upload the picture it says that the file is too large to use here, i take that to mean that the name chage has worked, but somehow add to the file size (there's a file size limit here). so the way i do it is change the extension from a .bmp to .jpg useing irfan view. i know there must be a simpler way of doing this. can you tell me how? thanks :)
     
  2. gerardwil

    gerardwil Registered Member

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    Open the *.bmp and then in Irfan view use save as *.jpg
     
  3. iceni60

    iceni60 ( ^o^)

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    thanks, gerardwil. that's what i do. i just thought there maybe a quicker/easier way of doing it like just changing the name of the extension. maybe not then. thanks gerardwil for your help :)
     
  4. MikeBCda

    MikeBCda Registered Member

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    Unfortunately you're talking about entirely different graphics formats, so a simple re-name would normally get you no more than the equivalent of "Huh?? Can't read this" from most viewers. But there's all kinds of graphics programs around that'll neatly convert between formats, like the one gerardwil suggested.

    My personal favorite, Graphics Workshop Pro, can go one step further -- it can look at a graphics file that has an incorrect extension, usually determine correctly what format it really is, and rename it appropriately.
     
  5. Notok

    Notok Registered Member

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    You can get the Irfanview Shell Extension that makes changing file formats a whole lot easier. Once installed you can right click on a file and choose what format you want it to be in the "Irfanview" menu item.
    Get it at
    http://www.baxbex.com/products.html
    (scroll down to the bottom)
     
  6. iceni60

    iceni60 ( ^o^)

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    that sounds perfect, Notok. i was hoping there'd be something like that, i'll try it when i get home. thanks
    and thanks too MikeBCda for your help :) . i'll make a note of Graphics Workshop Pro and take alook at it sometime

    thank you all, as always, great advice :)
     
  7. bigc73542

    bigc73542 Retired Moderator

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    you can change format in MS paint also.
     
  8. iceni60

    iceni60 ( ^o^)

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    about half an hour ago i renamed, for example-

    picture.jpg to picture.bmp

    i dont think i have any software that would help make that change, but it worked. the .jpg changed into a .bmp . i checked the sizes of the images before and after, and the size stayed the same

    im going to go to the test forum and see if i can post a picture with its extensioned changed in that way. am i not understanding your explanations, or is it unusual to be able to change a picture's extension just by renameing it?
     
  9. Tassie_Devils

    Tassie_Devils Global Moderator

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    Hi Ice.... Just some extra info for you on top of advice given :)

    bmp format is not a commonly used one, as it's an extremely high resolution/information format in that it contains lots of data/resolution so that it can be sized up/down better for converting to printing formats mainly. Hence the high file sizes in that format. :)

    jpeg is a 'compression' format in that you compress a lot of the resolution/information mainly for "viewing" purposes, but the format is editable if saved at a high enough resolution in the first place for either viewing or printing.

    The jpeg quality, while it looks fine on a screen, is nowhere near the same as a bmp for printing, unless it's very high res, but that then defeats the purpose of using it for viewing on a web with the high file size.

    It's also a "lossy" format, ie, it 'loses' resolution easily and does not reproduce very good unless near the top end of resolution quality.

    Try saving one at say a 30% quality [or 70% depends on how your particular program determines the quality] and then one at 80% Quality, you will start to see 'banding' at the lower end particularly in blends, where it does a 'jump' from one shade to the other and not a smooth transistion.

    PNG on the other hand, can also be used as a very good compromise as it's a "lossless" format, does not lose quality for viewing if compressed a fair way. It's generally half way between a GIF and JPEG in size.

    eps format is the top quality format we use in printing.
    High file size, but format is common for printing/quality purposes.

    I use GIF mainly for screenshots, as it's a very low file size format, you can see enough with it and only for viewing. Lousy printing quality.

    Try to use GIF if possible, as that saves on filesize, for forum purposes, sometimes I may have to convert to say an 80-90% jpeg to get a better image, particularly if it contains a lot of colour blends, but mainly GIFs are fine. :)

    screenie here is GIF, quality is pretty good considering format, and this size pic is only 28.5Kb. :D

    same file saved as:

    jpeg [100% quality]: 153Kb

    bmp: 604Kb

    png: 65Kb [Note the size, higher than GIF, but lower than jpeg and on my screen no difference in viewing between the PNG and the JPEG ones.

    eps: 615Kb

    Note the bmp and eps formats...:) Huge difference in file size.

    Cheers, TAS
     

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    Last edited: Sep 15, 2004
  10. iceni60

    iceni60 ( ^o^)

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    Thanks, Tassie. great post. i'd never even heard of a .eps .i've alot to learn about artwork and their extensions etc. never mind computers as a whole. o_O

    so what is happened when i renamed my .jpg on my desktop to a .bmp? i checked, and the format is really changing from a .jpg to a .bmp. the icon changes accordingly from the jpg icon to a bmp icon. however, from what you just explained it seems that the size/dimension should change too, because the quality of a jpg is not the same as a bmp. but the dimentions stayed the same and the size stayed the same too when i made the changes
     
  11. iceni60

    iceni60 ( ^o^)

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    i just read your reply in the test forum. it makes alittle more sense now. i hope you see this post before you re-explain your test forum explaination :) sorry if you dont :(
     
  12. Tassie_Devils

    Tassie_Devils Global Moderator

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    The file size cannot change... you are merely changing an extension... not a size...

    Your program has to be the one to 'edit' the file SIZE change when it's saved, via the program, into a particular format...

    I shall post a couple of screenies showing you difference ok..

    Same shot but diff format and different resolution.

    Now.. this first shot is jpeg format, and saved at only 45% quality [my program, the higher the percentage, the higher the quality, some work opposite, ok]

    sample: jpeg at 45% quality... not perfect but still see nice blends in sky, wording is fine, with slight deterioration around edges. Size is 45.5Kb

    TAS
     

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  13. Tassie_Devils

    Tassie_Devils Global Moderator

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    still jpeg at 30% quality. Size is only 13.5KB.... but, see how lousy the quality is.

    It's "lost" its resolution as I explained in a lossy format compression.

    ugggh, horrible...

    TAS
     

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  14. Tassie_Devils

    Tassie_Devils Global Moderator

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    now this is GIF format...

    size is 30.5Kb... it's still a good shot, clear, etc. but.. notice the "banding" I spoke of in first post.

    gif format does not handle any colour blends very good. but the rest of the pic is fine considering. The Icon, type all sharp and clear.

    TAS
     

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  15. iceni60

    iceni60 ( ^o^)

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    yep, i think you're finally getting it through my thick head.
    so, your saying, if i hadnt spent all night down the pub, posts 12 and 13 would look different?

    THANKS TASSIE
     
  16. Tassie_Devils

    Tassie_Devils Global Moderator

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    Hey Ice.. no probs mate.

    Love graphics, so it was not a bother. :D

    graphics extensions, wow, there are heaps, some you already know, some you wont.

    jpeg: joint photographic experts group, commonly shortened to jpg to allow the 3 letter extension given, although most proggy will read both extensions, especially with a MAC. JPEG compression methods do not decompress to the exact original image, but for most practical uses, humans cannot distinguish the expanded JEPG images from the original images. JPEG compression can store thousands or even millions of colors.

    bmp: Windows Bitmap. A file or image structure representing, bit for bit, an image displayed on a monitor. Bitmaps define the width and height of images and the parts of images. Bitmaps may represent colored images; in this case, more than one bit is needed to define each pixel. So the file sizes are large.

    gif: Graphic Interchange Format [static or animated]. A file compression method developed byCompuServe. The method reduces file sizes by counting repeating pixels and storing the pixel color and the number of repetitions. GIF compression is well suited for line art and simple images. GIF compression reduces image colors to no more than 256 colors. Hence the banding effects in blending colours.

    eps: Encapsulated Postscript. Magazines/Newspapers use eps for virtually all their picture/file formats. You can use a publishing program itself to change a document to an eps, which will include words, graphics, art, pictures, etc.
    A type of formatting in which positions and vectors describe images. Postscript formatted information is embedded into files for display or printing. Abbreviated as EPS. EPS is used for Postscript graphics files that are to be incorporated into other documents as most programs allow the import of EPSs.

    edit: I had a list of descriptions set out for work for training my scanner/graphic manipulating operators, which I got from a graphic file format site but cannot find site at the moment. But it's bascially the same as I copied from my notes for work.

    then there are lots more.

    wmf: Windows Metafile
    wgp: WordPerfect
    ras: SUN Raster
    pct: Macintosh Picture
    msp: MS Paint
    tga: Targa

    List goes on.. :p

    TAS
     
    Last edited: Sep 16, 2004
  17. Tassie_Devils

    Tassie_Devils Global Moderator

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    ROFL... maybe you see ALL things like post 13, after a night at the pub.

    TAS
     
  18. iceni60

    iceni60 ( ^o^)

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    seriously though for second, thanks for taking the time to explain it all so clearly, it really has helped alot :) thanks again Tass

    i hope you dont mind, but i sharpened up your image for you just to show i havent really spent the evening down the pub :eek:
     

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  19. Tassie_Devils

    Tassie_Devils Global Moderator

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    misunderstood Ice.... thought you were joking... sorry. so edited, my post when I read your reply below. Sent you PM.

    TAS :oops:
     
    Last edited: Sep 16, 2004
  20. iceni60

    iceni60 ( ^o^)

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    i feel really bad for having done that now, well, give me abit of time, and it'll give me a good reason to use what you've shown me to make a, i dont know, maybe a Tassie wallpaper :D maybe check the test forum sometime soon. i'll get out of this thread now before im kicked out the forum :oops: :D
     
  21. Tassie_Devils

    Tassie_Devils Global Moderator

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    Hi Ice... :)

    I thought you were joking, so replied in kind. :(

    .. but re-reading your post, I feel I may have been mistaken... if so.. :oops: I am sorry!!!

    Anytime you want help, just ask... only too willing to do so mate. :):):)

    Cheers, TAS
     
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