torden/ngx_img_filter

ngx_img_filter

• Based on the ngx_image_filter

Patch

• Fix : broken image when resizing trensparent png image

New Features

• Output all images as webp for Mobile
• Allow Quality options to work alone
• Add PNG Compress Level (=Quality) : 0 -> none, 1-9 -> level, -1 -> default

Directives

Directive	Default	Context	Syntax
img_filter_convert_webp	[on|off]	location	img_filter_convert_webp on;
img_filter_convert_allow_only_quality	[on|off]	location	img_filter_convert_allow_only_quality on;
img_filter_png_quality	-1	location	img_filter_png_quality 9;

Directives Example

img_filter resize                       $resize_width $resize_hegith;
img_filter_jpeg_quality                 $quality_jepg;
img_filter_webp_quality                 $quality_webp;
img_filter_buffer                       16M;
img_filter_transparency                 on;
img_filter_interlace                    off;
img_filter_convert_webp                 on;
img_filter_png_quality                  9;
img_filter_convert_allow_only_quality   on;

Compress quality

Image Format	Range
Jpeg	Compression quality (0-95, 0 means use the default)
Webp	Compression quality (0-100)
Png	compression level: 0 -> none, 1-9 -> level, -1 -> default
Gif	N/A

Requirements

• webp, gif, jpeg, png, libgd

Install (RockyLinux 8 or Higher)

# Install image libs
dnf install -y zlib \
zlib-devel \
zlib-static \
libpng \
libpng-devel \
libtiff \
libtiff-devel \
giflib \
giflib-devel \
libwebp \
libwebp-devel \
libvpx \
libvpx-devel \
curl \
libcurl-devel \
freetype-devel \
fontconfig-devel \
libXpm-devel \
libjpeg-turbo-devel \
openjpeg2-devel \
graphite2-devel \
libraqm-devel

# Install LIBIMAGQUANT
export VER_LIBIMGQUANT=2.18.0
wget https://github.com/ImageOptim/libimagequant/archive/refs/tags/${VER_LIBIMGQUANT}.tar.gz
tar xvzf ${VER_LIBIMGQUANT}.tar.gz
cd libimagequant-${VER_LIBIMGQUANT}
./configure --prefix=/usr/local/libimagequant --with-openmp=static
make -j4
make install
echo "/usr/local/libimagequant/lib" >> /etc/ld.so.conf
ldconfig

# Install libgd
export VER_LIBGD=2.3.3
wget https://github.com/libgd/libgd/releases/download/gd-${VER_LIBGD}/libgd-${VER_LIBGD}.tar.gz
tar xvzf libgd-${VER_LIBGD}.tar.gz
cd libgd-${VER_LIBGD}
./configure --prefix=/usr/local/libgd --with-liq=/usr/local/libimagequant
make -j4
make install
echo "/usr/local/libgd/lib" >> /etc/ld.so.conf
ldconfig

# Install Nginx
./configure --prefix=/usr/local/nginx --add-module=./ngx_img_filter
make
make install