fmt

Reply image format. Specifies the image encoding format for image data sent to the client and the corresponding response MIME type for the HTTP response header.

fmt= *format*[,[ *pixelType*][, *tiffCompression*]]

format

jpeg

Lossy JPEG.

jpg

Lossy JPG.

png

Loss-less PNG.

png-alpha

Loss-less PNG with alpha channel.

tif

TIFF.

tif-alpha

TIFF with alpha channel.

swf

Lossy JPEG embedded into a Macromedia swf file.

swf-alpha

Lossy JPEG and a deflate-compressed Mask embedded into a Macromedia swf file.

pdf

Image embedded in PDF.

eps

Uncompressed binary Encapsulated PostScript.

gif

GIF with 256 colors.

gif-alpha

GIF with 255 colors plus key-color transparency.

pixelType

rgb

Return RGB image data.

gray

Return gray-scale image data.

cmyk

Return CMYK image data.

tiffCompression

none

Uncompressed.

lzw

LZW (Lempel-Ziv-Welch) compression (lossless).

zip

"Deflate" compression (lossless).

jpeg

JPEG compression (lossy).

pixelType effects output color space conversion when icc= is not specified; the default color profile corresponding to pixelType is applied. If color management is disabled, naïve conversion is applied. pixelType is ignored when icc= is specified, which determines the output pixel type.

compression is permitted only if tif, tif-alpha, or PDF is specified as the format. Refer to the table below for the compression options supported for these image formats.

qlt- sets the JPEG encoding options for these formats: JPEG, TIFF with JPEG compression, PDF with JPEG compression, and SWF file. Use quantize= if fmt=gif or fmt=gif-alpha. Refer to the command descriptions for details. The other formats do not have settable options.

8-bits per pixel component are returned for all formats and pixel types.

The following table lists the valid combinations of format and pixelType, the corresponding HTTP response MIME types, whether ICC profiles can be embedded (see iccEmbed=), and what format-specific option commands can be applied.

format

pixelType

Response MIME Type

Embed ICC Profile

Options

jpeg, jpg

rgb, gray, cmyk

<image/jpeg>

Yes

qlt=

png, png-alpha

rgb, gray

<image/png>

Yes

png8, png8-alpha

rgb

<image/png>

yes

tif, tif-alpha

rgb, gray, cmyk

<image/tiff>

Yes

tiffCompression

(none|lzw|zip|jpeg), pathEmbed=, qlt

( qlt= is ignored unless tiffCompression is set to 'jpeg'.)

swf, swf-alpha

rgb, gray

<application/x-shockwave-flash>

No

(The Flash Player ignores embedded ICC profiles.)

qlt= , attribute::TrustedDomains

pdf

rgb, gray, cmyk

<application/pdf>

Yes

tiffCompression

(none|zip|jpeg),qlt=

( qlt= is ignored unless tiffCompression is set to 'jpeg'.)

eps

rgb, gray, cmyk

<image/eps>

Yes

pathEmbed=

gif, gif-alpha

rgb, gray

(Data is converted to palette after conversion to gray or rgb.)

<image/gif>

No

Specifies encoding format for reply image data sent to the client and the corresponding response MIME type for the HTTP reply header.

png-alpha returns unassociated alpha (that is, alpha does not pre-multiply the pixel values), while tif-alpha, and swf-alpha return associated alpha (that is, the alpha values are pre-multiplied with the alpha values). The alpha channel corresponds to the inverse of the vignette’s background mask for req=img, and to the group or object mask in case of req=object. To apply alpha when using a nested IR request, add fmt= with the appropriate alpha file format to the embedded IR request and the main request. No alpha data is returned if a CMYK or grayscale ICC profile is specified with icc=.

Properties

May occur anywhere in the request.

Default

format defaults to attribute::Formatand tiffCompression defaults to attribute::TiffEncoding. pixelType defaults to rgb if icc= is not specified, otherwise it corresponds to the pixel type of the specified ICC profile.

See also

attribute::Format , attribute::JpegQuality, attribute::TiffEncoding, qlt=, iccEmbed=, pathEmbed=, req=, quantize=

On this page