An on-demand image filtering modules for Apache.
Will read local images, or proxy images from another server and apply transforms, convert formats and apply compression.
Uses Imagemagick.
- Apache 2.2.x
- Imagemagick 6.6+
- libcurl 7.18.0+
On Ubuntu or Debian, this should do the job:
apt install apache2-dev libmagickwand-dev libmagick++-dev libmagickcore-dev libcurl4-gnutls-dev libtool build-essential automake
./autorun.sh --with-imagemagick=/path/to/imagemagick --with-apache=/path/to/apache
The paths provided above are prefix paths used to install those dependencies. If you installed Imagemagick and Apache (including APR) in /usr/local you would run:
./autorun.sh --with-imagemagick=/usr/ --with-apache=/usr/
make
make install # probably want to sudo this
** Assumiung installation into /usr/**
Load the module in `/etc/apache2/mods-available/dims.load
LoadModule dims_module /usr/lib/apache2/modules/mod_dims.so
Symlink to enable
ln -s /etc/apache2/mods-available/dims.load apache2/mods-enabled/dims.load
Restart apache.
In your vhost:
AddHandler dims-local .gif .jpg
<Location /dims/>
SetHandler dims
</Location>
<Location /dims-status/>
SetHandler dims-status
</Location>
<Location /dims3/>
SetHandler dims3
</Location>
DimsDefaultImageURL http://images.example.com/404.jpg
DimsAddClient mydims http://images.example.com/404.jpg 86400
DimsAddWhiteList images.example.com
DimsImageMagickTimeout 5000
DimsDownloadTimeout 5000
<Location /dims-status/>
SetHandler dims-status
</Location>
<Location /dims-sizer/>
SetHandler dims-sizer
</Location>
Thumbnail an image (resize and crop): http://my.dims.server/dims3/mydims/thumbnail/100x100/http://images.example.com/image.jpg
Resize an image and flip it: http://my.dims.server/dims3/mydims/resize/100x100/flip/true/http://images.example.com/image.jpg
Get image dimensions: http://my.dims.server/dims-sizer/http://images.example.com/image.jpg ->
{
"height": 661,
"width": 990
}
modulate/<brightness>,<saturation>,<hue>
- brightness: 0 (black) - 100 (normal) - 9999 (completely bleached out)
- saturation: 0 (grey) - 100 (normal) - 9999 (aliens)
- hue: 0 (shift colour wheel left 180 deg) - 100 (normal) - 200 (shift right 180 deg)
Equalises the curves for a cheap 'punchy' effect.
normalize
Flips the image and renders it below the original. Useful for making quick and dirty background images or repeaters.
mirroredfloor
Flips an imagea. (Upside down)
flip
Flops an image. (Left to right)
flop
Resize that honours aspect ratio of original so that image is no larger than new width x height.
resize/<width>x<height>
sharpen/<radius>,<sigma>
- radius: 0- (pixels, controls size of convolution)
- sigma: 0- (pixels, controls rolloff of gaussian used, typically sqrt(radius) for normal usage, e.g.
sharpen/4,2)
Fast resample for small thumbnails which also crops to exactly requested size.
thumbnail/<width>x<height>
crop/<width>x<height>+<x>+<y>
format/<jpg|png|gif>
quality/<factor>
- quality: 1-100 (only affects JPG output)
blur/<radius>,<sigma>
- radius: 0- (pixels, controls size of convolution)
- sigma: 0- (pixels, controls rolloff of gaussian used, typically sqrt(radius) for normal usage, e.g.
blur/9,3. sigma > radius gives interesting effects)
brightness/<brightness>,<contrast>
- brightness: -100 - 100
- contrast: -100 - 100
flipflop/<axis>
- axis: horizontal | vertical
sepia/<threshold>
- threshold: 0-100
(Faster than desaturate)
grayscale/<true|false>
autolevel/<true|false>
invert/<true|false>
rotate/<angle>
- angle: 0-359
There are three classes of errors in mod_dims:
-
Errors caused during downloading of a source image. These come directly from libcurl and are logged as-is.
-
Errors caused during an ImageMagick operation. These come directly from ImageMagik and are logged as-is.
-
Errors caused during processing of a request by
mod_dims. These fall into the category of bad input checking, bad config, etc.
[client <client ip address> Imagemagick operation, '<operation>', timed out after 4 ms
<operation> would be something like "Resize/Image" or "Save/Image".
Errors will be in the following format in Apache's error log:
[client <client ip address>] <source> error, '<source error message>', on request: <request uri>
For example:
[client 10.181.182.244] Imagemagick error, 'no decode delegate for this image
format `'', on request: /20080803WI55426251_WI.jpg/TEST/thumbnail/78x100/
These message are usually self explanatory so no explain is provided. The URL that failed will be logged along with this message.
- Couldn't connect to server
- Couldn't resolve DNS
- Timeout was reached
- Requested URL has hostname that is not in the whitelist. (aaolcdn.com)
- Application ID is not valid
- Parsing thumbnail geometry failed
- Parsing crop geometry failed
- Failed to read image. This occurs if ImageMagick had trouble reading the image.
- Unable to stat image file. This occurs when a local request is unable to find the image to resize.
- Memory allocation failed. This should rarely occur, if ever, but usually when it does it's the result of an ImageMagick timeout.
- unrecognized image format
- no decode delegate for this image format. This happens when ImageMagick doesn't no how to read a source image.
- zero-length blob not permitted. This may occur if there was a failure to download the source image.
- Unsupported marker type 0x03. This may occur if the image is corrupted. The "0x03" may be different depending on the corruption.
Any errors that have "Assertion failed" are results of bugs in the code and can be considered serious.
Assertion failed: (wand->signature == WandSignature), function MagickGetImageFormat, file wand/magick-image.c, line 4137.