Fast HTTP microservice written in Go for high-level image processing backed by bimg and libvips. imaginary can be used as private or public HTTP service for massive image processing with first-class support for Docker & Fly.io.
It's almost dependency-free and only uses net/http native package without additional abstractions for better performance.
Supports multiple image operations exposed as a simple HTTP API, with additional optional features such as API token authorization, URL signature protection, HTTP traffic throttle strategy and CORS support for web clients.
imaginary can read images from HTTP POST payloads, server local path or remote HTTP servers, supporting JPEG, PNG, WEBP, HEIF, and optionally TIFF, PDF, GIF and SVG formats if [email protected]+ is compiled with proper library bindings.
imaginary is able to output images as JPEG, PNG and WEBP formats, including transparent conversion across them.
imaginary optionally supports image placeholder fallback mechanism in case of image processing error or server error of any nature, hence an image will be always returned by imaginary even in case of error, trying to match the requested image size and format type transparently. The error details will be provided in the response HTTP header Error field serialized as JSON.
imaginary uses internally libvips, a powerful and efficient library written in C for fast image processing
which requires a low memory footprint
and it's typically 4x faster than using the quickest ImageMagick and GraphicsMagick
settings or Go native image package, and in some cases it's even 8x faster processing JPEG images.
To get started, take a look the installation steps, usage cases and API docs.
- Supported image operations
 - Prerequisites
 - Installation
 - Recommended resources
 - Production notes
 - Scalability
 - Clients
 - Performance
 - Benchmark
 - Command-line usage
 - HTTP API
 - Logging
 - Authors
 - License
 
- Resize
 - Enlarge
 - Crop
 - SmartCrop (based on libvips built-in algorithm)
 - Rotate (with auto-rotate based on EXIF orientation)
 - AutoRotate with further image transformations (based on EXIF metadata orientation)
 - Flip (with auto-flip based on EXIF metadata)
 - Flop
 - Zoom
 - Thumbnail
 - Fit
 - Pipeline of multiple independent image transformations in a single HTTP request.
 - Configurable image area extraction
 - Embed/Extend image, supporting multiple modes (white, black, mirror, copy or custom background color)
 - Watermark (customizable by text)
 - Watermark image
 - Custom output color space (RGB, black/white...)
 - Format conversion (with additional quality/compression settings)
 - Info (image size, format, orientation, alpha...)
 - Reply with default or custom placeholder image in case of error.
 - Blur
 
- libvips 8.8+ (8.9+ recommended)
 - C compatible compiler such as gcc 4.6+ or clang 3.0+
 - Go 1.12+
 
go get -u github.com/h2non/imaginaryAlso, be sure you have the latest version of bimg:
go get -u github.com/h2non/bimgRun the following script as sudo (supports OSX, Debian/Ubuntu, Redhat, Fedora, Amazon Linux):
curl -s https://raw.githubusercontent.com/h2non/bimg/master/preinstall.sh | sudo bash -The install script requires curl and pkg-config
See Dockerfile for image details.
Fetch the image (comes with latest stable Go and libvips versions)
docker pull h2non/imaginary
Start the container with optional flags (default listening on port 9000)
docker run -p 9000:9000 h2non/imaginary -cors
Start the container enabling remote URL source image processing via GET requests and url query param.
docker run -p 9000:9000 h2non/imaginary -p 9000 -enable-url-source
Start the container enabling local directory image process via GET requests and file query param.
docker run -p 9000:9000 h2non/imaginary -p 900 -mount /volume/images
Start the container in debug mode:
docker run -p 9000:9000 -e "DEBUG=*" h2non/imaginary
Enter to the interactive shell in a running container
sudo docker exec -it <containerIdOrName> bash
Stop the container
docker stop h2non/imaginary
For more usage examples, see the command line usage.
All Docker images tags are available here.
You can add imaginary to your docker-compose.yml file:
version: "3"
services:
  imaginary:
    image: h2non/imaginary:latest
    # optionally mount a volume as local image source
    volumes:
      - images:/mnt/data
    environment:
       PORT: 9000
    command: -enable-url-source -mount /mnt/data
    ports:
      - "9000:9000"Deploy imaginary in seconds close to your users in Fly.io cloud by clicking on the button below:
Fly is a platform for applications that need to run globally. It runs your code close to users and scales compute in cities where your app is busiest. Write your code, package it into a Docker image, deploy it to Fly's platform and let that do all the work to keep your app snappy.
You can learn more about how Fly.io can reduce latency and provide a better experience by serving traffic close to your users location.
Learn more about how to run a custom deployment of imaginary on the Fly.io cloud.
Assuming you have cloudfoundry account, bluemix or pivotal and command line utility installed.
Clone this repository:
git clone https://github.com/h2non/imaginary.git
Push the application
cf push -b https://github.com/yacloud-io/go-buildpack-imaginary.git imaginary-inst01 --no-start
Define the library path
cf set-env imaginary-inst01 LD_LIBRARY_PATH /home/vcap/app/vendor/vips/lib
Start the application
cf start imaginary-inst01
Click to deploy on Google Cloud Run:
Given the multithreaded native nature of Go, in terms of CPUs, most cores means more concurrency and therefore, a better performance can be achieved. From the other hand, in terms of memory, 512MB of RAM is usually enough for small services with low concurrency (<5 requests/second). Up to 2GB for high-load HTTP service processing potentially large images or exposed to an eventual high concurrency.
If you need to expose imaginary as public HTTP server, it's highly recommended to protect the service against DDoS-like attacks.
imaginary has built-in support for HTTP concurrency throttle strategy to deal with this in a more convenient way and mitigate possible issues limiting the number of concurrent requests per second and caching the awaiting requests, if necessary.
In production focused environments it's highly recommended to enable the HTTP concurrency throttle strategy in your imaginary servers.
The recommended concurrency limit per server to guarantee a good performance is up to 20 requests per second.
You can enable it simply passing a flag to the binary:
$ imaginary -concurrency 20
In case you are experiencing any persistent unreleased memory issues in your deployment, you can try passing this environment variables to imaginary:
MALLOC_ARENA_MAX=2 imaginary -p 9000 -enable-url-source
When you use a cluster, it is necessary to control how the deployment is executed, and it is very useful to finish the containers in a controlled manner.
You can use the next command:
$ ps auxw | grep 'bin/imaginary' | awk 'NR>1{print buf}{buf = $2}' | xargs kill -TERM > /dev/null 2>&1
If you're looking for a large scale solution for massive image processing, you should scale imaginary horizontally, distributing the HTTP load across a pool of imaginary servers.
Assuming that you want to provide a high availability to deal efficiently with, let's say, 100 concurrent req/sec, a good approach would be using a front end balancer (e.g: HAProxy) to delegate the traffic control flow, ensure the quality of service and distribution the HTTP across a pool of servers:
        |==============|
        |  Dark World  |
        |==============|
              ||||
        |==============|
        |   Balancer   |
        |==============|
           |       |
          /         \
         /           \
        /             \
 /-----------\   /-----------\
 | imaginary |   | imaginary | (*n)
 \-----------/   \-----------/
Feel free to send a PR if you created a client for other language.
libvips is probably the faster open source solution for image processing. Here you can see some performance test comparisons for multiple scenarios:
- libvips speed and memory usage
 - bimg (Go library with C bindings to libvips)
 
See benchmark.sh for more details
Environment: Go 1.4.2. libvips-7.42.3. OSX i7 2.7Ghz
Requests  [total]       200
Duration  [total, attack, wait]   10.030639787s, 9.949499515s, 81.140272ms
Latencies [mean, 50, 95, 99, max]   83.124471ms, 82.899435ms, 88.948008ms, 95.547765ms, 104.384977ms
Bytes In  [total, mean]     23443800, 117219.00
Bytes Out [total, mean]     175517000, 877585.00
Success   [ratio]       100.00%
Status Codes  [code:count]      200:200
imaginary can deal efficiently with up to 20 request per second running in a multicore machine,
where it crops a JPEG image of 5MB and spending per each request less than 100 ms
The most expensive image operation under high concurrency scenarios (> 20 req/sec) is the image enlargement, which requires a considerable amount of math operations to scale the original image. In this kind of operation the required processing time usually grows over the time if you're stressing the server continuously. The advice here is as simple as taking care about the number of concurrent enlarge operations to avoid server performance bottlenecks.
Usage:
  imaginary -p 80
  imaginary -cors
  imaginary -concurrency 10
  imaginary -path-prefix /api/v1
  imaginary -enable-url-source
  imaginary -disable-endpoints form,health,crop,rotate
  imaginary -enable-url-source -allowed-origins http://localhost,http://server.com,http://*.example.org
  imaginary -enable-url-source -enable-auth-forwarding
  imaginary -enable-url-source -authorization "Basic AwDJdL2DbwrD=="
  imaginary -enable-placeholder
  imaginary -enable-url-source -placeholder ./placeholder.jpg
  imaginary -enable-url-signature -url-signature-key 4f46feebafc4b5e988f131c4ff8b5997
  imaginary -enable-url-source -forward-headers X-Custom,X-Token
  imaginary -h | -help
  imaginary -v | -version
Options:
  -a <addr>                 Bind address [default: *]
  -p <port>                 Bind port [default: 8088]
  -h, -help                 Show help
  -v, -version              Show version
  -path-prefix <value>      Url path prefix to listen to [default: "/"]
  -cors                     Enable CORS support [default: false]
  -gzip                     Enable gzip compression (deprecated) [default: false]
  -disable-endpoints        Comma separated endpoints to disable. E.g: form,crop,rotate,health [default: ""]
  -key <key>                Define API key for authorization
  -mount <path>             Mount server local directory
  -http-cache-ttl <num>     The TTL in seconds. Adds caching headers to locally served files.
  -http-read-timeout <num>  HTTP read timeout in seconds [default: 60]
  -http-write-timeout <num> HTTP write timeout in seconds [default: 60]
  -enable-url-source        Enable remote HTTP URL image source processing (?url=http://..)
  -enable-placeholder       Enable image response placeholder to be used in case of error [default: false]
  -enable-auth-forwarding   Forwards X-Forward-Authorization or Authorization header to the image source server. -enable-url-source flag must be defined. Tip: secure your server from public access to prevent attack vectors
  -forward-headers          Forwards custom headers to the image source server. -enable-url-source flag must be defined.
  -enable-url-signature     Enable URL signature (URL-safe Base64-encoded HMAC digest) [default: false]
  -url-signature-key        The URL signature key (32 characters minimum)
  -allowed-origins <urls>   Restrict remote image source processing to certain origins (separated by commas). Note: Origins are validated against host *AND* path.
  -max-allowed-size <bytes> Restrict maximum size of http image source (in bytes)
  -max-allowed-resolution <megapixels> Restrict maximum resolution of the image [default: 18.0]
  -certfile <path>          TLS certificate file path
  -keyfile <path>           TLS private key file path
  -authorization <value>    Defines a constant Authorization header value passed to all the image source servers. -enable-url-source flag must be defined. This overwrites authorization headers forwarding behavior via X-Forward-Authorization
  -placeholder <path>       Image path to image custom placeholder to be used in case of error. Recommended minimum image size is: 1200x1200
  -concurrency <num>        Throttle concurrency limit per second [default: disabled]
  -burst <num>              Throttle burst max cache size [default: 100]
  -mrelease <num>           OS memory release interval in seconds [default: 30]
  -cpus <num>               Number of used cpu cores.
                            (default for current machine is 8 cores)
  -log-level                Set log level for http-server. E.g: info,warning,error [default: info].
                            Or can use the environment variable GOLANG_LOG=info.
Start the server in a custom port:
imaginary -p 8080Also, you can pass the port as environment variable:
PORT=8080 imaginaryEnable HTTP server throttle strategy (max 10 requests/second):
imaginary -p 8080 -concurrency 10
Enable remote URL image fetching (then you can do GET request passing the url=http://server.com/image.jpg query param):
imaginary -p 8080 -enable-url-source
Mount local directory (then you can do GET request passing the file=image.jpg query param):
imaginary -p 8080 -mount ~/images
Enable authorization header forwarding to image origin server. X-Forward-Authorization or Authorization (by priority) header value will be forwarded as Authorization header to the target origin server, if one of those headers are present in the incoming HTTP request.
Security tip: secure your server from public access to prevent attack vectors when enabling this option:
imaginary -p 8080 -enable-url-source -enable-auth-forwarding
Or alternatively you can manually define an constant Authorization header value that will be always sent when fetching images from remote image origins. If defined, X-Forward-Authorization or Authorization headers won't be forwarded, and therefore ignored, if present.
Note:
imaginary -p 8080 -enable-url-source -authorization "Bearer s3cr3t"
Send fixed caching headers in the response. The headers can be set in either "cache nothing" or "cache for N seconds". By specifying 0 imaginary will send the "don't cache" headers, otherwise it sends headers with a TTL. The following example informs the client to cache the result for 1 year:
imaginary -p 8080 -enable-url-source -http-cache-ttl 31556926
Enable placeholder image HTTP responses in case of server error/bad request.
The placeholder image will be dynamically and transparently resized matching the expected image widthxheight define in the HTTP request params.
Also, the placeholder image will be also transparently converted to the desired image type defined in the HTTP request params, so the API contract should be maintained as much better as possible.
This feature is particularly useful when using imaginary as public HTTP service consumed by Web clients.
In case of error, the appropriate HTTP status code will be used to reflect the error, and the error details will be exposed serialized as JSON in the Error response HTTP header, for further inspection and convenience for API clients.
imaginary -p 8080 -enable-placeholder -enable-url-source
You can optionally use a custom placeholder image.
Since the placeholder image should fit a variety of different sizes, it's recommended to use a large image, such as 1200x1200.
Supported custom placeholder image types are: JPEG, PNG and WEBP.
imaginary -p 8080 -placeholder=placeholder.jpg -enable-url-source
Enable URL signature (URL-safe Base64-encoded HMAC digest).
This feature is particularly useful to protect against multiple image operations attacks and to verify the requester identity.
imaginary -p 8080 -enable-url-signature -url-signature-key 4f46feebafc4b5e988f131c4ff8b5997
It is recommended to pass key as environment variables:
URL_SIGNATURE_KEY=4f46feebafc4b5e988f131c4ff8b5997 imaginary -p 8080 -enable-url-signature
Increase libvips threads concurrency (experimental):
VIPS_CONCURRENCY=10 imaginary -p 8080 -concurrency 10
Enable debug mode:
DEBUG=* imaginary -p 8080
Or filter debug output by package:
DEBUG=imaginary imaginary -p 8080
Disable info logs:
GOLANG_LOG=error imaginary -p 8080
Reading a local image (you must pass the -mount=<directory> flag):
curl -O "http://localhost:8088/crop?width=500&height=400&file=foo/bar/image.jpg"
Fetching the image from a remote server (you must pass the -enable-url-source flag):
curl -O "http://localhost:8088/crop?width=500&height=400&url=https://raw.githubusercontent.com/h2non/imaginary/master/testdata/large.jpg"
Crop behaviour can be influenced with the gravity parameter. You can specify a preference for a certain region (north, south, etc.). To enable Smart Crop you can specify the value "smart" to autodetect the most interesting section to consider as center point for the crop operation:
curl -O "http://localhost:8088/crop?width=500&height=200&gravity=smart&url=https://raw.githubusercontent.com/h2non/imaginary/master/testdata/smart-crop.jpg"
imaginary exposes an ugly HTML form for playground purposes in: http://localhost:8088/form
imaginary can be configured to block all requests for images with a src URL this is not specified in the allowed-origins list. Imaginary will validate that the remote url matches the hostname and path of at least one origin in allowed list. Perhaps the easiest way to show how this works is to show some examples.
allowed-origins setting | 
image url | is valid | 
|---|---|---|
-allowed-origins https://s3.amazonaws.com/some-bucket/ | 
s3.amazonaws.com/some-bucket/images/image.png | 
VALID | 
-allowed-origins https://s3.amazonaws.com/some-bucket/ | 
s3.amazonaws.com/images/image.png | 
NOT VALID (no matching basepath) | 
-allowed-origins https://s3.amazonaws.com/some-* | 
s3.amazonaws.com/some-bucket/images/image.png | 
VALID | 
-allowed-origins https://*.amazonaws.com/some-bucket/ | 
anysubdomain.amazonaws.com/some-bucket/images/image.png | 
VALID | 
-allowed-origins https://*.amazonaws.com | 
anysubdomain.amazonaws.comimages/image.png | 
VALID | 
-allowed-origins https://*.amazonaws.com | 
www.notaws.comimages/image.png | 
NOT VALID (no matching host) | 
-allowed-origins https://*.amazonaws.com, foo.amazonaws.com/some-bucket/ | 
bar.amazonaws.com/some-other-bucket/image.png | 
VALID (matches first condition but not second) | 
imaginary supports a simple token-based API authorization.
To enable it, you should pass the -key flag to the binary.
API token can be defined as HTTP header (API-Key) or query param (key).
Example request with API key:
POST /crop HTTP/1.1
Host: localhost:8088
API-Key: secret
The URL signature is provided by the sign request parameter.
The HMAC-SHA256 hash is created by taking the URL path (including the leading /), the request parameters (alphabetically-sorted and concatenated with & into a string). The hash is then base64url-encoded.
Here an example in Go:
signKey  := "4f46feebafc4b5e988f131c4ff8b5997"
urlPath  := "/resize"
urlQuery := "file=image.jpg&height=200&type=jpeg&width=300"
h := hmac.New(sha256.New, []byte(signKey))
h.Write([]byte(urlPath))
h.Write([]byte(urlQuery))
buf := h.Sum(nil)
fmt.Println("sign=" + base64.RawURLEncoding.EncodeToString(buf))
imaginary will always reply with the proper HTTP status code and JSON body with error details.
Here an example response error when the payload is empty:
{
  "message": "Cannot read payload: no such file",
  "code": 1
}See all the predefined supported errors here.
If -enable-placeholder or -placeholder <image path> flags are passed to imaginary, a placeholder image will be used in case of error or invalid request input.
If -enable-placeholder is passed, the default imaginary placeholder image will be used, however you can customized it via -placeholder flag, loading a custom compatible image from the file system.
Since imaginary has been partially designed to be used as public HTTP service, including web pages, in certain scenarios the response MIME type must be respected,
so the server will always reply with a placeholder image in case of error, such as image processing error, read error, payload error, request invalid request or any other.
You can customize the placeholder image passing the -placeholder <image path> flag when starting imaginary.
In this scenarios, the error message details will be exposed in the Error response header field as JSON for further inspection from API clients.
In some edge cases the placeholder image resizing might fail, so a 400 Bad Request will be used as response status and the Content-Type will be application/json with the proper message info. Note that this scenario won't be common.
If you're pushing images to imaginary as multipart/form-data (you can do it as well as image/*), you must define at least one input field called file with the raw image data in order to be processed properly by imaginary.
Complete list of available params. Take a look to each specific endpoint to see which params are supported. Image measures are always in pixels, unless otherwise indicated.
- width       
int- Width of image area to extract/resize - height      
int- Height of image area to extract/resize - top         
int- Top edge of area to extract. Example:100 - left        
int- Left edge of area to extract. Example:100 - areawidth   
int- Height area to extract. Example:300 - areaheight  
int- Width area to extract. Example:300 - quality     
int- JPEG image quality between 1-100. Defaults to80 - compression 
int- PNG compression level. Default:6 - palette     
bool- Enable 8-bit quantisation. Works with only PNG images. Default:false - rotate      
int- Image rotation angle. Must be multiple of90. Example:180 - factor      
int- Zoom factor level. Example:2 - margin      
int- Text area margin for watermark. Example:50 - dpi         
int- DPI value for watermark. Example:150 - textwidth   
int- Text area width for watermark. Example:200 - opacity     
float- Opacity level for watermark text or watermark image. Default:0.2 - flip        
bool- Transform the resultant image with flip operation. Default:false - flop        
bool- Transform the resultant image with flop operation. Default:false - force       
bool- Force image transformation size. Default:false - nocrop      
bool- Disable crop transformation. Defaults depend on the operation - noreplicate 
bool- Disable text replication in watermark. Defaults tofalse - norotation  
bool- Disable auto rotation based on EXIF orientation. Defaults tofalse - noprofile   
bool- Disable adding ICC profile metadata. Defaults tofalse - stripmeta   
bool- Remove original image metadata, such as EXIF metadata. Defaults tofalse - text        
string- Watermark text content. Example:copyright (c) 2189 - font        
string- Watermark text font type and format. Example:sans bold 12 - color       
string- Watermark text RGB decimal base color. Example:255,200,150 - image       
string- Watermark image URL pointing to the remote HTTP server. - type        
string- Specify the image format to output. Possible values are:jpeg,png,webpandauto.autowill use the preferred format requested by the client in the HTTP Accept header. A client can provide multiple comma-separated choices inAcceptwith the best being the one picked. - gravity     
string- Define the crop operation gravity. Supported values are:north,south,centre,west,eastandsmart. Defaults tocentre. - file        
string- Use image from server local file path. In order to use this you must pass the-mount=<dir>flag. - url         
string- Fetch the image from a remote HTTP server. In order to use this you must pass the-enable-url-sourceflag. - colorspace  
string- Use a custom color space for the output image. Allowed values are:srgborbw(black&white) - field       
string- Custom image form field name if usingmultipart/form. Defaults to:file - extend      
string- Extend represents the image extend mode used when the edges of an image are extended. Defaults tomirror. Allowed values are:black,copy,mirror,white,lastpixelandbackground. Ifbackgroundvalue is specified, you can define the desired extend RGB color viabackgroundparam, such as?extend=background&background=250,20,10. For more info, see libvips docs. - background  
string- Background RGB decimal base color to use when flattening transparent PNGs. Example:255,200,150 - sigma       
float- Size of the gaussian mask to use when blurring an image. Example:15.0 - minampl     
float- Minimum amplitude of the gaussian filter to use when blurring an image. Default: Example:0.5 - operations  
json- Pipeline of image operation transformations defined as URL safe encoded JSON array. See pipeline endpoints for more details. - sign        
string- URL signature (URL-safe Base64-encoded HMAC digest) - interlace   
bool- Use progressive / interlaced format of the image output. Defaults tofalse - aspectratio 
string- Apply aspect ratio by giving either image's height or width. Exampe:16:9 
Content-Type: application/json
Serves as JSON the current imaginary, bimg and libvips versions.
Example response:
{
  "imaginary": "0.1.28",
  "bimg": "1.0.5",
  "libvips": "8.4.1"
}Content-Type: application/json
Provides some useful statistics about the server stats with the following structure:
- uptime 
number- Server process uptime in seconds. - allocatedMemory 
number- Currently allocated memory in megabytes. - totalAllocatedMemory 
number- Total allocated memory over the time in megabytes. - goroutines 
number- Number of running goroutines. - cpus 
number- Number of used CPU cores. 
Example response:
{
  "uptime": 1293,
  "allocatedMemory": 5.31,
  "totalAllocatedMemory": 34.3,
  "goroutines": 19,
  "cpus": 8
}Content Type: text/html
Serves an ugly HTML form, just for testing/playground purposes
Accepts: image/*, multipart/form-data. Content-Type: application/json
Returns the image metadata as JSON:
{
  "width": 550,
  "height": 740,
  "type": "jpeg",
  "space": "srgb",
  "hasAlpha": false,
  "hasProfile": true,
  "channels": 3,
  "orientation": 1
}Accepts: image/*, multipart/form-data. Content-Type: image/*
Crop the image by a given width or height. Image ratio is maintained
- width 
int - height 
int - quality 
int(JPEG-only) - compression 
int(PNG-only) - type 
string - file 
string- Only GET method and if the-mountflag is present - url 
string- Only GET method and if the-enable-url-sourceflag is present - force 
bool - rotate 
int - embed 
bool - norotation 
bool - noprofile 
bool - flip 
bool - flop 
bool - stripmeta 
bool - extend 
string - background 
string- Example:?background=250,20,10 - colorspace 
string - sigma 
float - minampl 
float - gravity 
string - field 
string- Only POST andmultipart/formpayloads - interlace 
bool - aspectratio 
string 
Accepts: image/*, multipart/form-data. Content-Type: image/*
Crop the image by a given width or height using the libvips built-in smart crop algorithm.
- width 
int - height 
int - quality 
int(JPEG-only) - compression 
int(PNG-only) - type 
string - file 
string- Only GET method and if the-mountflag is present - url 
string- Only GET method and if the-enable-url-sourceflag is present - force 
bool - rotate 
int - embed 
bool - norotation 
bool - noprofile 
bool - flip 
bool - flop 
bool - stripmeta 
bool - extend 
string - background 
string- Example:?background=250,20,10 - colorspace 
string - sigma 
float - minampl 
float - gravity 
string - field 
string- Only POST andmultipart/formpayloads - interlace 
bool - aspectratio 
string 
Accepts: image/*, multipart/form-data. Content-Type: image/*
Resize an image by width or height. Image aspect ratio is maintained
- width 
intrequired - height 
int - quality 
int(JPEG-only) - compression 
int(PNG-only) - type 
string - file 
string- Only GET method and if the-mountflag is present - url 
string- Only GET method and if the-enable-url-sourceflag is present - embed 
bool - force 
bool - rotate 
int - nocrop 
bool- Defaults totrue - norotation 
bool - noprofile 
bool - stripmeta 
bool - flip 
bool - flop 
bool - extend 
string - background 
string- Example:?background=250,20,10 - colorspace 
string - sigma 
float - minampl 
float - field 
string- Only POST andmultipart/formpayloads - interlace 
bool - aspectratio 
string - palette 
bool 
Accepts: image/*, multipart/form-data. Content-Type: image/*
- width 
intrequired - height 
intrequired - quality 
int(JPEG-only) - compression 
int(PNG-only) - type 
string - file 
string- Only GET method and if the-mountflag is present - url 
string- Only GET method and if the-enable-url-sourceflag is present - embed 
bool - force 
bool - rotate 
int - nocrop 
bool- Defaults tofalse - norotation 
bool - noprofile 
bool - stripmeta 
bool - flip 
bool - flop 
bool - extend 
string - background 
string- Example:?background=250,20,10 - colorspace 
string - sigma 
float - minampl 
float - field 
string- Only POST andmultipart/formpayloads - interlace 
bool - palette 
bool 
Accepts: image/*, multipart/form-data. Content-Type: image/*
- top 
intrequired - left 
int - areawidth 
intrequired - areaheight 
int - width 
int - height 
int - quality 
int(JPEG-only) - compression 
int(PNG-only) - type 
string - file 
string- Only GET method and if the-mountflag is present - url 
string- Only GET method and if the-enable-url-sourceflag is present - embed 
bool - force 
bool - rotate 
int - norotation 
bool - noprofile 
bool - stripmeta 
bool - flip 
bool - flop 
bool - extend 
string - background 
string- Example:?background=250,20,10 - colorspace 
string - sigma 
float - minampl 
float - field 
string- Only POST andmultipart/formpayloads - interlace 
bool - aspectratio 
string - palette 
bool 
Accepts: image/*, multipart/form-data. Content-Type: image/*
- factor 
numberrequired - width 
int - height 
int - quality 
int(JPEG-only) - compression 
int(PNG-only) - type 
string - file 
string- Only GET method and if the-mountflag is present - url 
string- Only GET method and if the-enable-url-sourceflag is present - embed 
bool - force 
bool - rotate 
int - nocrop 
bool- Defaults totrue - norotation 
bool - noprofile 
bool - stripmeta 
bool - flip 
bool - flop 
bool - extend 
string - background 
string- Example:?background=250,20,10 - colorspace 
string - sigma 
float - minampl 
float - field 
string- Only POST andmultipart/formpayloads - interlace 
bool - aspectratio 
string - palette 
bool 
Accepts: image/*, multipart/form-data. Content-Type: image/*
- width 
intrequired - height 
intrequired - quality 
int(JPEG-only) - compression 
int(PNG-only) - type 
string - file 
string- Only GET method and if the-mountflag is present - url 
string- Only GET method and if the-enable-url-sourceflag is present - embed 
bool - force 
bool - rotate 
int - norotation 
bool - noprofile 
bool - stripmeta 
bool - flip 
bool - flop 
bool - extend 
string - background 
string- Example:?background=250,20,10 - colorspace 
string - sigma 
float - minampl 
float - field 
string- Only POST andmultipart/formpayloads - interlace 
bool - aspectratio 
string - palette 
bool 
Accepts: image/*, multipart/form-data. Content-Type: image/*
Resize an image to fit within width and height, without cropping. Image aspect ratio is maintained The width and height specify a maximum bounding box for the image.
- width 
intrequired - height 
intrequired - quality 
int(JPEG-only) - compression 
int(PNG-only) - type 
string - file 
string- Only GET method and if the-mountflag is present - url 
string- Only GET method and if the-enable-url-sourceflag is present - embed 
bool - force 
bool - rotate 
int - norotation 
bool - noprofile 
bool - stripmeta 
bool - flip 
bool - flop 
bool - extend 
string - background 
string- Example:?background=250,20,10 - colorspace 
string - sigma 
float - minampl 
float - field 
string- Only POST andmultipart/formpayloads - interlace 
bool - aspectratio 
string - palette 
bool 
Accepts: image/*, multipart/form-data. Content-Type: image/*
Accepts: image/*, multipart/form-data. Content-Type: image/*
Automatically rotate the image with no further image transformations based on EXIF orientation metadata.
Returns a new image with the same size and format as the input image.
- rotate 
intrequired - width 
int - height 
int - quality 
int(JPEG-only) - compression 
int(PNG-only) - type 
string - file 
string- Only GET method and if the-mountflag is present - url 
string- Only GET method and if the-enable-url-sourceflag is present - embed 
bool - force 
bool - norotation 
bool - noprofile 
bool - stripmeta 
bool - flip 
bool - flop 
bool - extend 
string - background 
string- Example:?background=250,20,10 - colorspace 
string - sigma 
float - minampl 
float - field 
string- Only POST andmultipart/formpayloads - interlace 
bool - aspectratio 
string - palette 
bool 
Accepts: image/*, multipart/form-data. Content-Type: image/*
- width 
int - height 
int - quality 
int(JPEG-only) - compression 
int(PNG-only) - type 
string - file 
string- Only GET method and if the-mountflag is present - url 
string- Only GET method and if the-enable-url-sourceflag is present - embed 
bool - force 
bool - norotation 
bool - noprofile 
bool - stripmeta 
bool - flip 
bool - flop 
bool - extend 
string - background 
string- Example:?background=250,20,10 - colorspace 
string - sigma 
float - minampl 
float - field 
string- Only POST andmultipart/formpayloads - interlace 
bool - aspectratio 
string - palette 
bool 
Accepts: image/*, multipart/form-data. Content-Type: image/*
- width 
int - height 
int - quality 
int(JPEG-only) - compression 
int(PNG-only) - type 
string - file 
string- Only GET method and if the-mountflag is present - url 
string- Only GET method and if the-enable-url-sourceflag is present - embed 
bool - force 
bool - norotation 
bool - noprofile 
bool - stripmeta 
bool - flip 
bool - flop 
bool - extend 
string - background 
string- Example:?background=250,20,10 - colorspace 
string - sigma 
float - minampl 
float - field 
string- Only POST andmultipart/formpayloads - interlace 
bool - aspectratio 
string - palette 
bool 
Accepts: image/*, multipart/form-data. Content-Type: image/*
- type 
stringrequired - quality 
int(JPEG-only) - compression 
int(PNG-only) - file 
string- Only GET method and if the-mountflag is present - url 
string- Only GET method and if the-enable-url-sourceflag is present - embed 
bool - force 
bool - rotate 
int - norotation 
bool - noprofile 
bool - stripmeta 
bool - flip 
bool - flop 
bool - extend 
string - background 
string- Example:?background=250,20,10 - colorspace 
string - sigma 
float - minampl 
float - field 
string- Only POST andmultipart/formpayloads - interlace 
bool - aspectratio 
string - palette 
bool 
Accepts: image/*, multipart/form-data. Content-Type: image/*
This endpoint allow the user to declare a pipeline of multiple independent image transformation operations all in a single HTTP request.
Note: a maximum of 10 independent operations are current allowed within the same HTTP request.
Internally, it operates pretty much as a sequential reducer pattern chain, where given an input image and a set of operations, for each independent image operation iteration, the output result image will be passed to the next one, as the accumulated result, until finishing all the operations.
In imperative programming, this would be pretty much analog to the following code:
var image
for operation in operations {
  image = operation.Run(image, operation.Options)
}- operations 
jsonrequired- URL safe encoded JSON with a list of operations. See below for interface details. - file 
string- Only GET method and if the-mountflag is present - url 
string- Only GET method and if the-enable-url-sourceflag is present 
Self-documented JSON operation schema:
[
  {
    "operation": string, // Operation name identifier. Required.
    "ignore_failure": boolean, // Ignore error in case of failure and continue with the next operation. Optional.
    "params": map[string]mixed, // Object defining operation specific image transformation params, same as supported URL query params per each endpoint.
  }
]- crop - Same as 
/cropendpoint. - smartcrop - Same as 
/smartcropendpoint. - resize - Same as 
/resizeendpoint. - enlarge - Same as 
/enlargeendpoint. - extract - Same as 
/extractendpoint. - rotate - Same as 
/rotateendpoint. - autorotate - Same as 
/autorotateendpoint. - flip - Same as 
/flipendpoint. - flop - Same as 
/flopendpoint. - thumbnail - Same as 
/thumbnailendpoint. - zoom - Same as 
/zoomendpoint. - convert - Same as 
/convertendpoint. - watermark - Same as 
/watermarkendpoint. - watermarkImage - Same as 
/watermarkimageendpoint. - blur - Same as 
/blurendpoint. 
[
  {
    "operation": "crop",
    "params": {
      "width": 500,
      "height": 300
    }
  },
  {
    "operation": "watermark",
    "params": {
      "text": "I need some covfete",
      "font": "Verdana",
      "textwidth": 100,
      "opacity": 0.8
    }
  },
  {
    "operation": "rotate",
    "params": {
      "rotate": 180
    }
  },
  {
    "operation": "convert",
    "params": {
      "type": "webp"
    }
  }
]Accepts: image/*, multipart/form-data. Content-Type: image/*
- text 
stringrequired - margin 
int - dpi 
int - textwidth 
int - opacity 
float - noreplicate 
bool - font 
string - color 
string - quality 
int(JPEG-only) - compression 
int(PNG-only) - type 
string - file 
string- Only GET method and if the-mountflag is present - url 
string- Only GET method and if the-enable-url-sourceflag is present - embed 
bool - force 
bool - rotate 
int - norotation 
bool - noprofile 
bool - stripmeta 
bool - flip 
bool - flop 
bool - extend 
string - background 
string- Example:?background=250,20,10 - colorspace 
string - sigma 
float - minampl 
float - field 
string- Only POST andmultipart/formpayloads - interlace 
bool - palette 
bool 
Accepts: image/*, multipart/form-data. Content-Type: image/*
- image 
stringrequired- URL to watermark image, example:?image=https://logo-server.com/logo.jpg - top 
int- Top position of the watermark image - left 
int- Left position of the watermark image - opacity 
float- Opacity value of the watermark image - quality 
int(JPEG-only) - compression 
int(PNG-only) - type 
string - file 
string- Only GET method and if the-mountflag is present - url 
string- Only GET method and if the-enable-url-sourceflag is present - embed 
bool - force 
bool - rotate 
int - norotation 
bool - noprofile 
bool - stripmeta 
bool - flip 
bool - flop 
bool - extend 
string - background 
string- Example:?background=250,20,10 - colorspace 
string - sigma 
float - minampl 
float - field 
string- Only POST andmultipart/formpayloads - interlace 
bool - palette 
bool 
Accepts: image/*, multipart/form-data. Content-Type: image/*
- sigma 
floatrequired - minampl 
float - width 
int - height 
int - quality 
int(JPEG-only) - compression 
int(PNG-only) - type 
string - file 
string- Only GET method and if the-mountflag is present - url 
string- Only GET method and if the-enable-url-sourceflag is present - embed 
bool - force 
bool - norotation 
bool - noprofile 
bool - stripmeta 
bool - flip 
bool - flop 
bool - extend 
string - background 
string- Example:?background=250,20,10 - colorspace 
string - field 
string- Only POST andmultipart/formpayloads - interlace 
bool - aspectratio 
string - palette 
bool 
Imaginary uses an apache compatible log format.
You can ingest Imaginary logs with fluentd using the following fluentd config :
# use your own tag name (*.imaginary for this example)
<filter *.imaginary>
    @type parser
    key_name log
    reserve_data true
    <parse>
        @type multi_format
        # access logs parser
        <pattern>
            format regexp
            expression /^[^ ]* [^ ]* [^ ]* \[(?<time>[^\]]*)\] "(?<method>\S+)(?: +(?<path>[^ ]*) +\S*)?" (?<code>[^ ]*) (?<size>[^ ]*) (?<response_time>[^ ]*)$/
            types code:integer,size:integer,response_time:float
            time_key time
            time_format %d/%b/%Y %H:%M:%S
        </pattern>
        # warnings / error logs parser
        <pattern>
            format none
            message_key message
        </pattern>
    </parse>
</filter>
<match *.imaginary>
    @type rewrite_tag_filter
    # Logs with code field are access logs, and logs without are error logs
    <rule>
        key code
        pattern ^.+$
        tag ${tag}.access
    </rule>
    <rule>
        key code
        pattern ^.+$
        invert true
        tag ${tag}.error
    </rule>
</match>
In the end, access records are tagged with *.imaginary.access, and warning /
error records are tagged with *.imaginary.error.
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- Tomás Aparicio - Original author and maintainer.
 
MIT - Tomas Aparicio