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Difference between revisions of "HttpImageFilterModule"

(Directives)
(image_filter_jpeg_quality)
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Sets the rate of loss of information when processing the images as '''JPEG'''. The maximum recommended value is '''95'''.
 
Sets the rate of loss of information when processing the images as '''JPEG'''. The maximum recommended value is '''95'''.
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== image_filter_sharpen ==
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<include wikitext nopre src="http://wiki.nginx.org/nginx.org/ngx_http_image_filter_module/image_filter_sharpen.txt" />
  
 
== image_filter_transparency ==
 
== image_filter_transparency ==

Revision as of 18:16, 30 April 2012

Contents

Synopsis

Version: 0.7.54+

This module is a filter for transforming JPEG, GIF and PNG images. It is not enabled by default to enable it, provide this option to ./configure when building nginx:

--with-http_image_filter_module 

libgd is required to build and run the module. We recommend using the latest version of libgd.


Example Configuration

location /img/ {
    proxy_pass     http://backend;
    image_filter   resize  150 100;
    error_page     415   = /empty;
}
 
location = /empty {
    empty_gif;
}

Directives

image_filter

ERROR in secure-include.php: could not read the given src URL http://wiki.nginx.org/nginx.org/ngx_http_image_filter_module/image_filter.txt

Specifies the type of transformation to apply to the image, one of the below:

  • test: checking that the response is indeed an image format JPEG, GIF or PNG. Otherwise, an error 415.
  • size: Gives information about the image in JSON format. For example,
{ "img" : { "width": 100, "height": 100, "type": "gif" } }

Or if an error occurs,

{}
  • resize: proportionally reduces the image to a specified size.
  • crop: proportionally reduces the image to a specified size and trims extra edge.

image_filter_buffer

ERROR in secure-include.php: could not read the given src URL http://wiki.nginx.org/nginx.org/ngx_http_image_filter_module/image_filter_buffer.txt

Sets the maximum size for reading the image.

image_filter_jpeg_quality

ERROR in secure-include.php: could not read the given src URL http://wiki.nginx.org/nginx.org/ngx_http_image_filter_module/image_filter_jpeg_quality.txt

Sets the rate of loss of information when processing the images as JPEG. The maximum recommended value is 95.

image_filter_sharpen

ERROR in secure-include.php: could not read the given src URL http://wiki.nginx.org/nginx.org/ngx_http_image_filter_module/image_filter_sharpen.txt

image_filter_transparency

ERROR in secure-include.php: could not read the given src URL http://wiki.nginx.org/nginx.org/ngx_http_image_filter_module/image_filter_transparency.txt

This directive allows you to disable image transparency in GIF and palette-based PNG to improve image resampling quality.

True color PNG alpha-channels are always preserved despite this setting.

Note: Grayscale PNG's are untested, but should be handled as truecolor PNGs.

References

Original Documentation