Method Image.JPEG.encode()
- Method
encode
string
encode(object
image
)
string
encode(string
|object
image
,mapping
options
)- Description
Encodes an
image
object with JPEG compression. The image may also be a string containing a raw JPEG image. In the Theoptions
argument may be a mapping containing zero or more encoding options:"quality"
:int(0..100)
Set quality of result. Default is 75.
"optimize"
:bool
Optimize Huffman table. Default is on (1) for images smaller than 50kpixels.
"progressive"
:bool
Make a progressive JPEG. Default is off (0).
"grayscale"
:bool
Make a grayscale JPEG instead of color (YCbCr).
"smooth"
:int(1..100)
Smooth input. Value is strength.
"method"
:int
DCT method to use. Any of IFAST, ISLOW, FLOAT, DEFAULT or FASTEST. DEFAULT and FASTEST is from the jpeg library, probably ISLOW and IFAST respectively.
"density_unit"
:int(0..2)
The unit used for x_density and y_density.
0
No unit
1
dpi
2
dpcm
"x_density"
:int
Density of image.
"y_density"
:int
"comment"
:string
Comment to be written in the JPEG file. Must not be a wide string.
"baseline"
:bool
Force baseline output. Useful for quality<25. Default is off for quality<25.
"quant_tables"
:mapping
(int
:array
(array
(int
)))Tune quantisation tables manually.
"marker"
:mapping
(int
:string(8bit)
|array
(string(8bit)
))Application and comment markers; the integer should be one of Marker.COM, Marker.APP0, Marker.APP1, ..., Marker.APP15. The string is up to the application; most notable are Adobe and Photoshop markers.
"transform"
:int
Lossless image transformation. Has only effect when supplying a JPEG file as indata.
FLIP_H
Flip image horizontally
FLIP_V
Flip image vertically
ROT_90
Rotate image 90 degrees clockwise
ROT_180
Rotate image 180 degrees clockwise
ROT_270
Rotate image 270 degrees clockwise
TRANSPOSE
Transpose image
TRANSVERSE
Transverse image
- Note
Please read some about JPEG files. A quality setting of 100 does not mean the result is lossless.