Image::Info - phpMan

NAME
    Image::Info - Extract meta information from image files

SYNOPSIS
     use Image::Info qw(image_info dim);

     my $info = image_info("image.jpg");
     if (my $error = $info->{error}) {
         die "Can't parse image info: $error\n";
     }
     my $color = $info->{color_type};

     my $type = image_type("image.jpg");
     if (my $error = $type->{error}) {
         die "Can't determine file type: $error\n";
     }
     die "No gif files allowed!" if $type->{file_type} eq 'GIF';

     my($w, $h) = dim($info);

DESCRIPTION
    This module provides functions to extract various kinds of meta
    information from image files.

  EXPORTS
    Exports nothing by default, but can export the following methods on
    request:

            image_info
            image_type
            dim
            html_dim
            determine_file_type

  METHODS
    The following functions are provided by the "Image::Info" module:

    image_info( $file )
    image_info( \$imgdata )
    image_info( $file, key => value,... )
        This function takes the name of a file or a file handle as argument
        and will return one or more hashes (actually hash references)
        describing the images inside the file. If there is only one image in
        the file only one hash is returned. In scalar context, only the hash
        for the first image is returned.

        In case of error, a hash containing the "error" key will be
        returned. The corresponding value will be an appropriate error
        message.

        If a reference to a scalar is passed as an argument to this
        function, then it is assumed that this scalar contains the raw image
        data directly.

        The "image_info()" function also take optional key/value style
        arguments that can influence what information is returned.

    image_type( $file )
    image_type( \$imgdata )
        Returns a hash with only one key, "file_type". The value will be the
        type of the file. On error, sets the two keys "error" and "Errno".

        This function is a dramatically faster alternative to the image_info
        function for situations in which you only need to find the image
        type.

        It uses only the internal file-type detection to do this, and thus
        does not need to load any of the image type-specific driver modules,
        and does not access to entire file. It also only needs access to the
        first 11 bytes of the file.

        To maintain some level of compatibility with image_info, image_type
        returns in the same format, with the same error message style. That
        is, it returns a HASH reference, with the "$type->{error}" key set
        if there was an error.

        On success, the HASH reference will contain the single key
        "file_type", which represents the type of the file, expressed as the
        type code used for the various drivers ('GIF', 'JPEG', 'TIFF' and so
        on).

        If there are multiple images within the file they will be ignored,
        as this function provides only the type of the overall file, not of
        the various images within it. This function will not return multiple
        hashes if the file contains multiple images.

        Of course, in all (or at least effectively all) cases the type of
        the images inside the file is going to be the same as that of the
        file itself.

    dim( $info_hash )
        Takes an hash as returned from "image_info()" and returns the
        dimensions ($width, $height) of the image. In scalar context returns
        the dimensions as a string.

    html_dim( $info_hash )
        Returns the dimensions as a string suitable for embedding directly
        into HTML or SVG <img>-tags. E.g.:

           print "<img src="..." @{[html_dim($info)]}>\n";

    determine_file_format( $filedata )
        Determines the file format from the passed file data (a normal Perl
        scalar containing the first bytes of the file), and returns either
        undef for an unknown file format, or a string describing the format,
        like "BMP" or "JPEG".

Image descriptions
    The "image_info()" function returns meta information about each image in
    the form of a reference to a hash. The hash keys used are in most cases
    based on the TIFF element names. All lower case keys are mandatory for
    all file formats and will always be there unless an error occurred (in
    which case the "error" key will be present.) Mixed case keys will only
    be present when the corresponding information element is available in
    the image.

    The following key names are common for any image format:

    file_media_type
        This is the MIME type that is appropriate for the given file format.
        The corresponding value is a string like: "image/png" or
        "image/jpeg".

    file_ext
        The is the suggested file name extension for a file of the given
        file format. The value is a 3 letter, lowercase string like "png",
        "jpg".

    width
        This is the number of pixels horizontally in the image.

    height
        This is the number of pixels vertically in the image. (TIFF uses the
        name ImageLength for this field.)

    color_type
        The value is a short string describing what kind of values the
        pixels encode. The value can be one of the following:

          Gray
          GrayA
          RGB
          RGBA
          CMYK
          YCbCr
          CIELab

        These names can also be prefixed by "Indexed-" if the image is
        composed of indexes into a palette. Of these, only "Indexed-RGB" is
        likely to occur.

        It is similar to the TIFF field "PhotometricInterpretation", but
        this name was found to be too long, so we used the PNG inspired term
        instead.

    resolution
        The value of this field normally gives the physical size of the
        image on screen or paper. When the unit specifier is missing then
        this field denotes the squareness of pixels in the image.

        The syntax of this field is:

           <res> <unit>
           <xres> "/" <yres> <unit>
           <xres> "/" <yres>

        The <res>, <xres> and <yres> fields are numbers. The <unit> is a
        string like "dpi", "dpm" or "dpcm" (denoting "dots per
        inch/cm/meter).

    SamplesPerPixel
        This says how many channels there are in the image. For some image
        formats this number might be higher than the number implied from the
        "color_type".

    BitsPerSample
        This says how many bits are used to encode each of samples. The
        value is a reference to an array containing numbers. The number of
        elements in the array should be the same as "SamplesPerPixel".

    Comment
        Textual comments found in the file. The value is a reference to an
        array if there are multiple comments found.

    Interlace
        If the image is interlaced, then this tells which interlace method
        is used.

    Compression
        This tells you which compression algorithm is used.

    Gamma
        A number.

    LastModificationTime
        A ISO date string

Supported Image Formats
    The following image file formats are supported:

    BMP This module supports the Microsoft Device Independent Bitmap format
        (BMP, DIB, RLE).

        For more information see Image::Info::BMP.

    GIF Both GIF87a and GIF89a are supported and the version number is found
        as "GIF_Version" for the first image. GIF files can contain multiple
        images, and information for all images will be returned if
        image_info() is called in list context. The Netscape-2.0 extension
        to loop animation sequences is represented by the "GIF_Loop" key for
        the first image. The value is either "forever" or a number
        indicating loop count.

    ICO This module supports the Microsoft Windows Icon Resource format
        (.ico).

    JPEG
        For JPEG files we extract information both from "JFIF" and "Exif"
        application chunks.

        "Exif" is the file format written by most digital cameras. This
        encode things like timestamp, camera model, focal length, exposure
        time, aperture, flash usage, GPS position, etc.

        The "Exif" spec can be found at:
        <http://www.exif.org/specifications.html>.

        The "color_type" element may have the following values: "Gray",
        "YCbCr", and "CMYK". Note that detecting "RGB" and "YCCK" currently
        does not work, but will hopefully in future.

    PNG Information from IHDR, PLTE, gAMA, pHYs, tEXt, tIME chunks are
        extracted. The sequence of chunks are also given by the "PNG_Chunks"
        key.

    PBM/PGM/PPM
        All information available is extracted.

    SVG Provides a plethora of attributes and metadata of an SVG vector
        graphic.

    TIFF
        The "TIFF" spec can be found at:
        <http://partners.adobe.com/public/developer/tiff/>

        The EXIF spec can be found at:
        <http://www.exif.org/specifications.html>

    WBMP
        wbmp files have no magic, so cannot be used with the normal
        Image::Info functions. See Image::Info::WBMP for more information.

    WEBP
        VP8 (lossy), VP8L (lossless) and VP8X (extended) files are
        supported. Sets the key "Animation" to true if the file is an
        animation. Otherwise sets the key "Compression" to either "VP8" or
        "Lossless".

    XBM See Image::Info::XBM for details.

    XPM See Image::Info::XPM for details.

CAVEATS
    While this module is fine for parsing basic image information like image
    type, dimensions and color depth, it is probably not good enough for
    parsing out more advanced information like EXIF data. If you want an
    up-to-date and tested EXIF parsing library, please use Image::ExifTool.

SEE ALSO
    Image::Size, Image::ExifTool

AUTHORS
    Copyright 1999-2004 Gisle Aas.

    See the CREDITS file for a list of contributors and authors.

    Tels - (c) 2006 - 2008.

    Current maintainer: Slaven Rezic - (c) 2008 - 2015.

LICENSE
    This library is free software; you can redistribute it and/or modify it
    under the same terms as Perl v5.8.8 itself.