README
¶
Image Server
An image server toolkit in Go (Golang)
Features
- HTTP server
- Resize / convert (GIFT, nfnt resize, Graphicsmagick)
- Cache (groupcache, Redis, Memcache, in memory)
- Gamma correction
- Fully modular
Examples
Demo
Click the images to see the URL parameters.
Resize
| Options | Result |
|---|---|
width=200(preserve aspect ratio) |
 |
height=200(preserve aspect ratio) |
 |
width=200&height=200(change aspect ratio) |
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width=200&height=200&mode=fit(fit in 200x200) |
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width=200&height=200&mode=fill(fill 200x200 and crop) |
 |
Animated GIF
| Original | Resized |
|---|---|
 |
 |
 |
 |
Gamma correction (more info)
| Original | Disabled | Enabled |
|---|---|---|
| Dalai Gamma |  |
 |
| Gray squares |  |
 |
| Random |  |
 |
| Rings |  |
 |
Resampling
| Resampling | Rings | Large |
|---|---|---|
| Nearest neighbor |  |
 |
| Box |  |
 |
| Linear |  |
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| Cubic |  |
 |
| Lanczos |  |
 |
Quality
| JPEG quality | Result |
|---|---|
| 5% |  |
| 10% |  |
| 50% |  |
Convert (JPEG to GIF)
Backward compatibility
There is no backward compatibility promises. If you want to use it, vendor it. It's always OK to change things to make things better. The API is not 100% correct in the first commit.
Documentation
¶
Overview ¶
Package imageserver provides an Image server toolkit.
Index ¶
- Constants
- func ImageEqual(im1, im2 *Image) bool
- type Handler
- type HandlerFunc
- type HandlerServer
- type Image
- type ImageError
- type ParamError
- type Params
- func (params Params) Empty() bool
- func (params Params) Get(key string) (interface{}, error)
- func (params Params) GetBool(key string) (bool, error)
- func (params Params) GetFloat(key string) (float64, error)
- func (params Params) GetInt(key string) (int, error)
- func (params Params) GetParams(key string) (Params, error)
- func (params Params) GetString(key string) (string, error)
- func (params Params) Has(key string) bool
- func (params Params) Keys() []string
- func (params Params) Len() int
- func (params Params) Set(key string, value interface{})
- func (params Params) String() string
- type Server
- type ServerFunc
- type SourceServer
Constants ¶
const ( // ImageFormatMaxLen is the maximum length for the image's format. ImageFormatMaxLen = 1 << 8 // 256 B // ImageDataMaxLen is the maximum length for the image's data. ImageDataMaxLen = 1 << 30 // 1 GiB )
const SourceParam = "source"
SourceParam is the source Param name.
Variables ¶
This section is empty.
Functions ¶
func ImageEqual ¶
ImageEqual compares two images and returns true if they are equal.
Types ¶
type HandlerFunc ¶
HandlerFunc is a Handler func.
type HandlerServer ¶
HandlerServer is a Handler Server.
type Image ¶
Image is a raw image.
Binary encoding:
- Format length (uint32)
- Format (string)
- Data length (uint32)
- Data([]byte)
Numbers are encoded using little-endian order.
func (*Image) MarshalBinary ¶
MarshalBinary implements encoding.BinaryMarshaler.
func (*Image) UnmarshalBinary ¶
UnmarshalBinary implements encoding.BinaryUnmarshaler.
It copies data then call UnmarshalBinaryNoCopy().
func (*Image) UnmarshalBinaryNoCopy ¶
UnmarshalBinaryNoCopy is like encoding.BinaryUnmarshaler but does no copy.
The caller must not reuse data after that.
type ImageError ¶
type ImageError struct {
Message string
}
ImageError is an Image error.
func (*ImageError) Error ¶
func (err *ImageError) Error() string
type ParamError ¶
ParamError is an error for a param.
func (*ParamError) Error ¶
func (err *ParamError) Error() string
type Params ¶
type Params map[string]interface{}
Params are params used in Image Server.
This is a wrapper around map[string]interface{} and provides utility methods. It should only contains basic Go types values (string, int float64, ...) or nested Params.
Getter methods return a *ParamError if the key does not exist or the type does not match.
type Server ¶
Server serves an Image.
func NewLimitServer ¶
NewLimitServer creates a new Server that limits the number of concurrent executions.
It uses a buffered channel to limit the number of concurrent executions.
type ServerFunc ¶
ServerFunc is a Server func.
type SourceServer ¶
type SourceServer struct {
Server
}
SourceServer is a source Server.
It forwards to the underlying Server with only the source param.
Source Files
Directories
¶
| Path | Synopsis |
|---|---|
|
Package cache provides an Image cache.
|
Package cache provides an Image cache. |
|
_test
Package _test provides utilities for Cache testing.
|
Package _test provides utilities for Cache testing. |
|
groupcache
Package groupcache provides a groupcache Image Server.
|
Package groupcache provides a groupcache Image Server. |
|
memcache
Package memcache provides a Memcache Image Cache.
|
Package memcache provides a Memcache Image Cache. |
|
memory
Package memory provides an in-memory Image Cache.
|
Package memory provides an in-memory Image Cache. |
|
redis
Package redis provides a Redis Image Cache.
|
Package redis provides a Redis Image Cache. |
|
examples
|
|
|
advanced
Package advanced provides an advanced example.
|
Package advanced provides an advanced example. |
|
simple
Package simple provides a simple example.
|
Package simple provides a simple example. |
|
Package graphicsmagick provides a GraphicsMagick Image Server.
|
Package graphicsmagick provides a GraphicsMagick Image Server. |
|
Package http provides a HTTP Handler for an Image Server.
|
Package http provides a HTTP Handler for an Image Server. |
|
gamma
Package gamma provides a imageserver/http.Parser implementation for imageserver/image/gamma.CorrectionProcessor.
|
Package gamma provides a imageserver/http.Parser implementation for imageserver/image/gamma.CorrectionProcessor. |
|
gift
Package gift provides a GIFT HTTP Parser
|
Package gift provides a GIFT HTTP Parser |
|
graphicsmagick
Package graphicsmagick provides a GraphicsMagick HTTP Parser.
|
Package graphicsmagick provides a GraphicsMagick HTTP Parser. |
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image
Package image provides imageserver/http.Parser implementations for imageserver/image.
|
Package image provides imageserver/http.Parser implementations for imageserver/image. |
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nfntresize
Package nfntresize provides a nfnt resize HTTP Parser.
|
Package nfntresize provides a nfnt resize HTTP Parser. |
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Package httpsource provides a HTTP source Image Server.
|
Package httpsource provides a HTTP source Image Server. |
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Package image provides a bridge to the Go image package.
|
Package image provides a bridge to the Go image package. |
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_test
Package _test provides utilities for Encoder testing.
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Package _test provides utilities for Encoder testing. |
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bmp
Package bmp provides a BMP Encoder.
|
Package bmp provides a BMP Encoder. |
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gamma
Package gamma provides gamma Processor and CorrectionProcessor.
|
Package gamma provides gamma Processor and CorrectionProcessor. |
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gif
Package gif provides a GIF Encoder, Handler, and Processor.
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Package gif provides a GIF Encoder, Handler, and Processor. |
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gift
Package gift provides a GIFT Processor.
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Package gift provides a GIFT Processor. |
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jpeg
Package jpeg provides a JPEG Encoder.
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Package jpeg provides a JPEG Encoder. |
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nfntresize
Package nfntresize provides a nfnt resize Processor.
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Package nfntresize provides a nfnt resize Processor. |
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png
Package png provides a PNG Encoder.
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Package png provides a PNG Encoder. |
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tiff
Package tiff provides a TIFF Encoder.
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Package tiff provides a TIFF Encoder. |