how to display the data of an image file

Collapse
This topic is closed.
X
X
 
  • Time
  • Show
Clear All
new posts
  • Kevin

    how to display the data of an image file

    Hi all,

    Assuming I have stored the binary data of an image file in a blob field
    of a table, how can I display it as an image in a web page? I found some
    instructions on the web, such as

    header('applica tion/octet-stream');
    echo $imgdata;

    I don't know why I always get this warning.

    ----------------
    Warning: Cannot modify header information
    -------------

    How can I get rid of it and show the image as an element of the current web
    page?

    Thanks, kevin





  • Lāʻie Techie

    #2
    Re: how to display the data of an image file

    On Fri, 25 Mar 2005 01:00:55 -0500, Kevin wrote:
    [color=blue]
    > Hi all,
    >
    > Assuming I have stored the binary data of an image file in a blob field of
    > a table, how can I display it as an image in a web page? I found some
    > instructions on the web, such as
    >
    > header('applica tion/octet-stream');
    > echo $imgdata;[/color]

    First mistake - send the proper Content-type header! If it's a JPEG, tell
    the browser it's a JPEG.
    [color=blue]
    >
    > I don't know why I always get this warning.
    >
    > ----------------
    > Warning: Cannot modify header information -------------
    >
    > How can I get rid of it and show the image as an element of the current
    > web page?[/color]

    That means some content was already sent. Check for any whitespace before
    your PHP code.

    HTH,
    La'ie Techie

    Comment

    • Monte Watson

      #3
      Re: how to display the data of an image file

      You can't have any html output before you issue the header command -
      even blank lines in any html blocks of code that might be on your page
      would be enough to give you that error. (I got this error alot when
      first learning php)

      I haven't worked with image binary data stored in a blob field, I've
      only used gd command libraries to create inline images. Maybe someone
      else can address that part of your question.

      Monte

      Kevin wrote:[color=blue]
      > Hi all,
      >
      > Assuming I have stored the binary data of an image file in a blob field
      > of a table, how can I display it as an image in a web page? I found some
      > instructions on the web, such as
      >
      > header('applica tion/octet-stream');
      > echo $imgdata;
      >
      > I don't know why I always get this warning.
      >
      > ----------------
      > Warning: Cannot modify header information
      > -------------
      >
      > How can I get rid of it and show the image as an element of the current web
      > page?
      >
      > Thanks, kevin
      >
      >
      >
      >
      >[/color]

      Comment

      • Kevin

        #4
        Re: how to display the data of an image file

        never mind, I have gotten the answer. thank you all.

        "L¨¡?ie Techie" <laie@win_remov e_get_nospam_so lutions.com> дÈëÓʼþ
        news:1111732373 .9ebc38615521a8 cd8e0f9fb66ebdd 2a6@teranews...[color=blue]
        > On Fri, 25 Mar 2005 01:00:55 -0500, Kevin wrote:
        >[color=green]
        > > Hi all,
        > >
        > > Assuming I have stored the binary data of an image file in a blob field[/color][/color]
        of[color=blue][color=green]
        > > a table, how can I display it as an image in a web page? I found some
        > > instructions on the web, such as
        > >
        > > header('applica tion/octet-stream');
        > > echo $imgdata;[/color]
        >
        > First mistake - send the proper Content-type header! If it's a JPEG, tell
        > the browser it's a JPEG.
        >[color=green]
        > >
        > > I don't know why I always get this warning.
        > >
        > > ----------------
        > > Warning: Cannot modify header information -------------
        > >
        > > How can I get rid of it and show the image as an element of the current
        > > web page?[/color]
        >
        > That means some content was already sent. Check for any whitespace before
        > your PHP code.
        >
        > HTH,
        > La'ie Techie
        >[/color]


        Comment

        • Chung Leong

          #5
          Re: how to display the data of an image file


          "La?ie Techie" <laie@win_remov e_get_nospam_so lutions.com> wrote in message
          news:1111732373 .9ebc38615521a8 cd8e0f9fb66ebdd 2a6@teranews...[color=blue]
          > On Fri, 25 Mar 2005 01:00:55 -0500, Kevin wrote:
          >[color=green]
          > > Hi all,
          > >
          > > Assuming I have stored the binary data of an image file in a blob field[/color][/color]
          of[color=blue][color=green]
          > > a table, how can I display it as an image in a web page? I found some
          > > instructions on the web, such as
          > >
          > > header('applica tion/octet-stream');
          > > echo $imgdata;[/color]
          >
          > First mistake - send the proper Content-type header! If it's a JPEG, tell
          > the browser it's a JPEG.[/color]

          Not much of a mistake, really, since modern browsers determine the image
          type from the data stream--not the mime header. Otherwise they wouldn't be
          able to load a HTML page sitting on a disk.

          You can actually use that fact to discourage people from saving images from
          your site. Just change the extension of all your image files to .tar.gz or
          something. When they're referenced in a img tag, the browser will spiff out
          the image type and display them correctly. When a user right click to save
          the file, it'll end up as a .tar.gz file and won't open.



          Comment

          • iz0nlee

            #6
            Re: how to display the data of an image file

            well what was it then?
            we all might have this problem at some future time
            regards
            "Kevin" <bird@village.o rg> wrote in message
            news:d20d04$bjl $1@mailhub227.i tcs.purdue.edu. ..[color=blue]
            > never mind, I have gotten the answer. thank you all.
            >
            > "L¨¡?ie Techie" <laie@win_remov e_get_nospam_so lutions.com> дÈëÓʼþ
            > news:1111732373 .9ebc38615521a8 cd8e0f9fb66ebdd 2a6@teranews...[color=green]
            >> On Fri, 25 Mar 2005 01:00:55 -0500, Kevin wrote:
            >>[color=darkred]
            >> > Hi all,
            >> >
            >> > Assuming I have stored the binary data of an image file in a blob field[/color][/color]
            > of[color=green][color=darkred]
            >> > a table, how can I display it as an image in a web page? I found some
            >> > instructions on the web, such as
            >> >
            >> > header('applica tion/octet-stream');
            >> > echo $imgdata;[/color]
            >>
            >> First mistake - send the proper Content-type header! If it's a JPEG,
            >> tell
            >> the browser it's a JPEG.
            >>[color=darkred]
            >> >
            >> > I don't know why I always get this warning.
            >> >
            >> > ----------------
            >> > Warning: Cannot modify header information -------------
            >> >
            >> > How can I get rid of it and show the image as an element of the current
            >> > web page?[/color]
            >>
            >> That means some content was already sent. Check for any whitespace
            >> before
            >> your PHP code.
            >>
            >> HTH,
            >> La'ie Techie
            >>[/color]
            >
            >[/color]


            Comment

            Working...