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 The options 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) 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.