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discourse-legacysite-perl/site/racecalendar/phpthumb/docs/phpthumb.readme.txt
dsainty 9797a6824a Fifth pass at adding key files
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//////////////////////////////////////////////////////////////
/// phpThumb() by James Heinrich <info@silisoftware.com> //
// available at http://phpthumb.sourceforge.net ///
//////////////////////////////////////////////////////////////
/// //
// This code is released under the GNU GPL: //
// http://www.gnu.org/copyleft/gpl.html //
// //
// +-----------------------------------------------+ //
// | phpThumb() is free to use according to the | //
// | terms of the GPL. Donations also gratefully | //
// | GPL FAQ: http://gnu.org/licenses/gpl-faq.html | //
// | | //
// | Donations are gratefully accepted from happy | //
// | users :) See http://phpthumb.sourceforge.net | //
// | | //
// | If you like phpThumb(), please consider | //
// | writing a review at HotScripts.com: | //
// | http://www.hotscripts.com/Detailed/25654.html | //
// | | //
// | If you do use this code somewhere, send me | //
// | an email and tell me how/where you used it. | //
// +-----------------------------------------------+ //
// ///
//////////////////////////////////////////////////////////////
============
Description:
============
phpThumb() uses the GD library to create thumbnails from
images (GIF, PNG or JPEG) on the fly. The output size is
configurable (can be larger or smaller than the source),
and the source may be the entire image or only a portion
of the original image. True color and resampling is used
if GD v2.0+ is available, otherwise low-color and simple
resizing is used. Source image can be a physical file on
the server or can be retrieved from a database. GIFs are
supported on all versions of GD even if GD does not have
native GIF support thanks to the GIFutil class by Fabien
Ezber. AntiHotlinking feature prevents other people from
using your server to resize their thumbnails, or link to
your images from another server. The cache feature
reduces server load.
======
Usage:
======
Call phpThumb() just like you would a normal image.
Examples:
<IMG SRC="phpThumb.php?src=/image.jpg&w=100">
<IMG SRC="phpThumb.php?src=http://example.com/foo.jpg">
See the "demo" link on http://phpthumb.sourceforge.net
for more usage examples). Parameters that can be passed
are listed below under "URL Parameters".
NOTE: It's recommended you use the local image filename
wherever possible (rather than http://) because performance
is much better, less (or no) use of temp files, and the
last-modified check for cached files doesn't work for
remote files.
To access files over a LAN with Windows share names you
must use the network name (or IP) and not a mapped drive
name, for example:
//othercomputer/file.jpg - good
//192.168.2.1/file.jpg - good
z:/file.jpg - won't work
This is a PHP limitation (see www.php.net/file-exists)
Note: you may want to use "/" slashes instead of "\" if
you have magic_quotes_gpc enabled to avoid stripslashes
problems, although either slash should work if
magic_quotes_gpc is disabled
================================
Alternate PATH_INFO-style Usage:
================================
phpThumb.php can also be called by passing parameters not
after the usual "?" but like this:
phpThumb.php/<params>=<values>;<w>x<h>;<image>
For example:
phpThumb.php/100;pic.jpg
phpThumb.php/100;images/pic.jpg
phpThumb.php/100;/images/pic.jpg
phpThumb.php/100x200;pic.jpg
phpThumb.php/x200;pic.jpg
phpThumb.php/f=jpeg;q=50;100x200;pic.jpg
phpThumb.php/fltr[]=usm;100;pic.jpg
<image> must be the last item. Dimensions must be the second-
last item. As many key/value pairs for parameters can be
passed before those last two items, with each pair joined by
equals ("=") and seperated by semicolon (";")
==============
Configuration:
==============
There are some configuration options you may (but are
not required to) change. Most configuration options can
be set when you call phpThumb() - see list below), but
default configuration options (such as cache directory)
are in phpThumb.config.php - this is the only file you
should ever modify.
The configuration file is distributed as
phpThumb.config.php.default to prevent accidental
overwriting of old configuration settings. Please
migrate your old settings to the new file (if upgrading),
or delete your old config and rename the default to
phpThumb.config.php
The amount of memory required for phpThumb depends on
several factors: the dimensions of the source image,
the dimensions of the output image, whether unsharp
masking is applied, whether watermarks are applied, etc.
The auto-detection of memory limits works as a general
"safe" value. You may be able to exceed the auto value
by a small or large amount, depending on whether you
apply watermarks and/or sharpening, and the output size
of your thumbnails. I do not currently have a reliable
formula for calculating such things, but I will attempt
to craft one for future versions of phpThumb(). Until
then, set "max_source_pixels" in phpThumb.config.php to a
value that works well for you (or leave it alone if the
defaults give you no problems).
The configuration options you should maybe modify are:
* cache_directory - thumbnailing is slow and processor-
intensive. Enabling caching will dramatically speed
up future thumbnail serving
* max_source_pixels - This should be auto-detected, but
if auto-detection fails and you get an invalid image
from large source images, set this to about 20% of
your available PHP memory limit.
* imagemagick_path - If the source image is larger than
max_source_pixels allows, but ImageMagick is available
phpThumb() will use it to generate the thumbnail.
///////////////////////////////////////////////////////////
Note: High-Security mode is recommended enabled if possible.
Set $PHPTHUMB_CONFIG['high_security_enabled'] in
phpThumb.config.php to enable it. Each call to phpThumb
needs to be made through the function supplied at the
bottom of phpThumb.config.php which create the hash:
require_once('phpThumb.config.php');
echo '<img src="'.phpThumbURL('src=pic.jpg&w=50').'">';
///////////////////////////////////////////////////////////
==============================================
Calling as an object (not using phpThumb.php):
==============================================
NOTE: most people don't need to and should not do this.
If you just want to display resized images, please just
use phpThumb.php, not the object mode. To render output
to one (or more) files instead of the browser, you should
skip phpThumb.php and instantiate your own object. Please
take a look at /demo/phpThumb.demo.object.php for details.
Note: phpThumb.php is where the caching code is located, if
you instantiate your own phpThumb() object that code is
bypassed and it's up to you to handle the reading and
writing of cached files.
===============
URL Parameters:
===============
src = filename of source image
new = create new image, not thumbnail of existing image.
Requires "w" and "h" parameters set.
[ex: &new=FF0000|75] - red background, 75% opacity
Set to hex color string of background. Opacity is
optional (defaults to 100% opaque).
w = max width of output thumbnail in pixels
h = max height of output thumbnail in pixels
wp = max width for portrait images
hp = max height for portrait images
wl = max width for landscape images
hl = max height for landscape images
ws = max width for square images
hs = max height for square images
f = output image format ("jpeg", "png", or "gif")
q = JPEG compression (1=worst, 95=best, 75=default)
sx = left side of source rectangle (default = 0)
(values 0 < sx < 1 represent percentage)
sy = top side of source rectangle (default = 0)
(values 0 < sy < 1 represent percentage)
sw = width of source rectangle (default = fullwidth)
(values 0 < sw < 1 represent percentage)
sh = height of source rectangle (default = fullheight)
(values 0 < sh < 1 represent percentage)
zc = zoom-crop. Will auto-crop off the larger dimension
so that the image will fill the smaller dimension
(requires both "w" and "h"). Set "zc=1" to enable.
(overrides both "iar" and "far")
bg = background hex color (default = FFFFFF)
bc = border hex color (default = 000000)
fltr = filter system. Call as an array as follows:
- "brit" (Brightness) [ex: &fltr[]=brit|<value>]
where <value> is the amount +/- to adjust brightness
(range -255 to 255)
Availble in PHP5 with bundled GD only.
- "cont" (Constrast) [ex: &fltr[]=cont|<value>]
where <value> is the amount +/- to adjust contrast
(range -255 to 255)
Availble in PHP5 with bundled GD only.
- "gam" (Gamma Correction) [ex: &fltr[]=gam|<value>]
where <value> can be a number >0 to 10+ (default 1.0)
Must be >0 (zero gives no effect). There is no max,
although beyond 10 is pretty useless. Negative
numbers actually do something, maybe not quite the
desired effect, but interesting nonetheless.
- "sat" (SATuration) [ex: &fltr[]=sat|<value>]
where <value> is a number between zero (no change)
and -100 (complete desaturation = grayscale), or it
can be any positive number for increased saturation.
- "ds" (DeSaturate) [ex: &fltr[]=ds|<value>]
is an alias for "sat" except values are inverted
(positive values remove color, negative values boost
saturation)
- "gray" (Grayscale) [ex: &fltr[]=gray]
remove all color from image, make it grayscale
- "th" (Threshold) [ex: &fltr[]=th|<value>]
makes image greyscale, then sets all pixels brighter
than <value> (range 0-255) to white, and all pixels
darker than <value> to black
- "rcd" (Reduce Color Depth) [ex: &fltr[]=rcd|<c>|<d>]
where <c> is the number of colors (2-256) you want
in the output image, and <d> is "1" for dithering
(deault) or "0" for no dithering
- "clr" (Colorize) [ex: &fltr[]=clr|<value>|<color>]
where <value> is a number between 0 and 100 for the
amount of colorization, and <color> is the hex color
to colorize to.
- "sep" (Sepia) [ex: &fltr[]=sep|<value>|<color>]
where <value> is a number between 0 and 100 for the
amount of colorization (default=50), and <color> is
the hex color to colorize to (default=A28065).
Note: this behaves differently when applied by
ImageMagick, in which case 80 is default, and lower
values give brighter/yellower images and higher
values give darker/bluer images
- "usm" (UnSharpMask) [ex: &fltr[]=usm|<a>|<r>|<t>]
where <a> is the amount (default = 80), <r> is the
radius (default = 0.5), <t> is the threshold
(default = 3).
- "blur" (Blur) [ex: &fltr[]=blur|<radius>]
where (0 < <radius> < 25) (default = 1)
- "gblr" (Gaussian Blur) [ex: &fltr[]=gblr]
Availble in PHP5 with bundled GD only.
- "sblr" (Selective Blur) [ex: &fltr[]=gblr]
Availble in PHP5 with bundled GD only.
- "smth" (Smooth) [ex: &fltr[]=smth|<value>]
where <value> is the weighting value for the matrix
(range -10 to 10, default 6)
Availble in PHP5 with bundled GD only.
- "lvl" (Levels) [ex: &fltr[]=lvl|<channel>|<min>|<max>
where <channel> can be one of 'r', 'g', 'b', 'a' (for
Red, Green, Blue, Alpha respectively), or '*' for all
channels based on average grayscale value (default).
<min> and <max> are the clip points for the levels
and are set to clip 0.1% of each end by default.
(range = 0-255) and are set to clip 0.1% of each end
by default. Use -1 for min and/or max to invoke auto-
detect mode. Using default parameters (&fltr[]=lvl)
is similar to Auto Contrast in Adobe Photoshop.
- "wb" (White Balance) [ex: &fltr[]=wb|<c>]
where <c> is the target hex color to white balance
on, this color is what "should be" white, or light
gray. The filter attempts to maintain brightness so
any gray color can theoretically be used. If <c> is
omitted the filter guesses based on brightest pixels
in each of RGB
- "hist" (Histogram)
[ex: &fltr[]=hist|<b>|<c>|<w>|<h>|<a>|<o>|<m>]
Where <b> is the color band(s) to display, from back
to front (one or more of "rgba*" for Red Green Blue
Alpha and Grayscale respectively);
<c> is a semicolon-seperated list of hex colors to
use for each graph band (defaults to FF0000, 00FF00,
0000FF, 999999, FFFFFF respectively);
<w> and <h> are the width and height of the overlaid
histogram in pixels, or if <= 1 then percentage of
source image width/height;
<a> is the alignment (same as for "wmi" and "wmt");
<o> is opacity from 0 (transparent) to 100 (opaque)
(requires PHP v4.3.2, otherwise 100% opaque);
<m> is the edge (and inter-tile) margin in percent
- "over" (OVERlay/underlay image) overlays an image on
the thumbnail, or overlays the thumbnail on another
image (to create a picture frame for example)
[ex: &fltr[]=over|<i>|<u>|<m>|<o>]
where <i> is the image filename; <u> is "0" (default)
for overlay the image on top of the thumbnail or "1"
for overlay the thumbnail on top of the image; <m> is
the margin - can be absolute pixels, or if < 1 is a
percentage of the thumbnail size [must be < 0.5]
(default is 0 for overlay and 10% for underlay);
<o> is opacity (0 = transparent, 100 = opaque)
(requires PHP v4.3.2, otherwise 100% opaque);
(thanks raynerape<70>gmail*com, shabazz3<7A>msu*edu)
- "wmi" (WaterMarkImage)
[ex: &fltr[]=wmi|<f>|<a>|<o>|<m>] where
<f> is the filename of the image to overlay;
<a> is the alignment (one of BR, BL, TR, TL, C,
R, L, T, B, *) where B=bottom, T=top, L=left,
R=right, C=centre, *=tile);
<o> is opacity from 0 (transparent) to 100 (opaque)
(requires PHP v4.3.2, otherwise 100% opaque);
<m> is the edge (and inter-tile) margin in percent
- "wmt" (WaterMarkText)
[ex: &fltr[]=wmt|<t>|<s>|<a>|<c>|<f>|<o>|<m>|<n>|<b>|<O>|<x>]
where:
<t> is the text to use as a watermark;
Any instance of metacharacters will be replaced
with their calculated value. Currently supported:
^Fb = source image filesize in bytes
^Fk = source image filesize in kilobytes
^Fm = source image filesize in megabytes
^X = source image width in pixels
^Y = source image height in pixels
^x = thumbnail width in pixels
^y = thumbnail height in pixels
^^ = the character ^
<s> is the font size (1-5 for built-in font, or point
size for TrueType fonts);
<a> is the alignment (one of BR, BL, TR, TL, C, R, L,
T, B, * where B=bottom, T=top, L=left, R=right,
C=centre, *=tile);
<c> is the hex color of the text;
<f> is the filename of the TTF file (optional, if
omitted a built-in font will be used);
<o> is opacity from 0 (transparent) to 100 (opaque)
(requires PHP v4.3.2, otherwise 100% opaque);
<m> is the edge (and inter-tile) margin in percent;
<n> is the angle
<b> is the hex color of the background;
<O> is background opacity from 0 (transparent) to
100 (opaque)
(requires PHP v4.3.2, otherwise 100% opaque);
<x> is the direction(s) in which the background is
extended (either 'x' or 'y' (or both, but both
will obscure entire image))
Note: works with TTF fonts only, not built-in
(thanks mail<69>mmjaeger*com, craig<69>pc-fanatics*com)
- "flip" [ex: &fltr[]=flip|x or &fltr[]=flip|y]
flip image on X or Y axis
- "ric" [ex: &fltr[]=ric|<x>|<y>]
rounds off the corners of the image (to transparent
for PNG output), where <x> is the horizontal radius
of the curve and <y> is the vertical radius
- "elip" [ex: &fltr[]=elip]
similar to rounded corners but more extreme
- "mask" [ex: &fltr[]=mask|filename.png]
greyscale values of mask are applied as the alpha
channel to the main image. White is opaque, black
is transparent.
- "bvl" (BeVeL) [ex: &fltr[]=bvl|<w>|<c1>|<c2>]
where <w> is the bevel width, <c1> is the hex color
for the top and left shading, <c2> is the hex color
for the bottom and right shading
- "bord" (BORDer) [ex: &fltr[]=bord|<w>|<rx>|<ry>|<c>
where <w> is the width in pixels, <rx> and <ry> are
horizontal and vertical radii for rounded corners,
and <c> is the hex color of the border
- "fram" (FRAMe) draws a frame, similar to "bord" but
more configurable
[ex: &fltr[]=fram|<w1>|<w2>|<c1>|<c2>|<c3>]
where <w1> is the width of the main border, <w2> is
the width of each side of the bevel part, <c1> is the
hex color of the main border, <c2> is the highlight
bevel color, <c3> is the shadow bevel color
- "drop" (DROP shadow)
[ex: &fltr[]=drop|<d>|<w>|<clr>|<a>]
where <d> is distance from image to shadow, <w> is
width of shadow fade (not yet implemented), <clr> is
the hex color of the shadow, and <a> is the angle of
the shadow (default=225)
file = if set then thumbnail will be rendered to this
filename, not output and not cached.
(Deprecated. Disabled by default since v1.6.0.
You should instantiate your own object instead)
goto = URL to redirect to after rendering image to file
* Must begin with "http://"
* Requires file parameter set
(Deprecated. Disabled by default since v1.6.0.
You should instantiate your own object instead)
err = custom error image filename instead of showing
error messages (for use on production sites)
md5s = MD5 hash of the source image -- if this parameter is
passed with the hash of the source image then the
source image is not checked for existance or
modification and the cached file is used (if
available). If 'md5s' is passed an empty string then
phpThumb.php dies and outputs the correct MD5 hash
value. This parameter is the single-file equivalent
of 'cache_source_filemtime_ignore_*' configuration
paramters
xto = EXIF Thumbnail Only - set to only extract EXIF
thumbnail and not do any additional processing
ra = Rotate by Angle: angle of rotation in degrees
positive = counterclockwise, negative = clockwise
ar = Auto Rotate: set to "x" to use EXIF orientation
stored by camera. Can also be set to "l" or "L"
for landscape, or "p" or "P" for portrait. "l"
and "P" rotate the image clockwise, "L" and "p"
rotate the image counter-clockwise.
aoe = Output Allow Enlarging - override the setting for
$CONFIG['output_allow_enlarging'] (1=on, 0=off)
("far" and "iar" both override this and allow output
larger than input)
iar = Ignore Aspect Ratio - disable proportional resizing
and stretch image to fit "h" & "w" (which must both
be set). (1=on, 0=off) (overrides "far")
far = Force Aspect Ratio - image will be created at size
specified by "w" and "h" (which must both be set).
Alignment: L=left,R=right,T=top,B=bottom,C=center
BL,BR,TL,TR use the appropriate direction if the
image is landscape or portrait.
maxb = MAXimum Byte size - output quality is auto-set to
fit thumbnail into "maxb" bytes (compression
quality is adjusted for JPEG, bit depth is adjusted
for PNG and GIF)
down = filename to save image to. If this is set the
browser will prompt to save to this filename rather
than display the image
==============
General Notes:
==============
* Always use the local image filename wherever possible
rather than a full http:// URL because performance is
much better, less (or no) use of temp files, and the
last-modified check for cached files doesn't work for
remote files. For example:
good: phpThumb.php?src=/images/nicepic.jpg
bad: phpThumb.php?src=/home/httpd/example/images/nicepic.jpg
worse: phpThumb.php?src=http://example.com/images/nicepic.jpg
* Thumbnails will be scaled proportionately to fit in a
box of at most (width * height) pixels
(unless "iar" is set)
* Thumbnail caching for URL or database sources requires
an absolute directory name for $config_cache_directory
Physical file cached thumbnails will be recreated if
the source file changes, but remote/database files
cannot (modification time isn't readily available)
* If you need a GUI interface to phpThumb(), or for a user
to specify crop settings, or something like that please
see the list of known programs in /demo/readme.demos.txt
* Cropping images can be specified with either exact pixel
values for sx/sy/sw/sh parameters, or if those are set
to a value >0 and <1 then these are interpreted as a
percentage of the source image width/height. For example,
to crop 25% off all sides, you would specify parameters:
phpThumb.php?src=pic.jpg&sx=.25&sy=.25&sw=.5&sh=.5
* phpThumb() may have tempfile access issues on servers
where Safe Mode is enabled, specificly when accessing
a file over HTTP, or when a non-bundled version of GD
is in use. Specifying "config_temp_directory" may help
* Properly resolving /~user/ style filenames requires
apache_lookup_uri(), which is missing or broken in
Apache2, or if PHP is not installed as an Apache module.
phpThumb() does try and work around this if it is
unavailble, but you may have to specify a full filename
for "src" if you encounter problems.
* phpThumb() should work with PHP v4.0.6+, but seems to
have a few quirks before v4.1.0
EXIF thumbnail extraction requires PHP v4.2.0+
Image rotation requires PHP v4.3.0+. There have been
reports of problems with PHP older than v4.3.3
Some image filters require PHP v5.0.0+
Run /demo/phpThumb.demo.check.php to examine your server
* phpThumb() works better and faster when ImageMagick is
available. Most functions will work with only GD2, but
speed is much faster with ImageMagick, and much larger
images can be processed with ImageMagick than GD.
* phpThumb() works with GD v1.x, but works better with
GD v2.0+ because of the true-color image support
and ImageCopyResampled(). Also, there appears to be a
bug in ImageCopyResized() which is used with GD v1.x
where the bottom and/or right line of pixels is set
to the background color (due to a rounding error?)
NOTE: Please use the bundled version of GD if at all
possible (with PHP v4.3.0+) because the non-bundled
version has bugs which may cause PHP to crash:
* http://bugs.php.net/bug.php?id=21518
* http://bugs.php.net/bug.php?id=24174
phpThumb() has a workaround for the above bug but
there may be other bugs, and the workaround is slow.
Alpha transparent output requires GD >= 2.0.1 and
PHP >= 4.3.2
Most (if not all) filters require GD v2.x to function
at all. But many filters can be handled by ImageMagick
instead of GD.
* Filters handled by ImageMagick or GD:
- brit;cont;ds;sat;gray;clr;sep;gam;neg;th;rcd;flip;edge;
emb;lvl;blur;gblr;usm;
* Filters handled only by ImageMagick:
- none yet
* Filters handled only by GD + PHP5:
- sblr;mean;smth;
* Filters handled only by GD2:
- bvl;wmi;wmt;over;wb;hist;fram;drop;mask;elip;ric;bord;
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