Image File Types and Associated Attributes

Attributes for Writing Image Files

The table below describes the attributes that you can specify for the image writers.

When you are writing images, you must specify the FORMAT= attribute. You can specify this attribute either directly as an argument for the WRITE command or as part of the image-path (if you use the LNAMEMK function to specify the pathname). For example:

/* Specify the FORMAT= attribute directly */
/* as an argument to the WRITE command.   */
rc=imgop(task-id,'WRITE','/user/images/sign.tif', 'format=tiff');

/* Use the LNAMEMK function to specify the image-path, */
/* and include the FORMAT= attribute as part of the path. */
path=lnamemk(5,'mine.images.sign','format=cat');
rc = imgop(task-id,'WRITE',path);

Image Formats for Writing
File Type	Writer Attributes	Comment
BMP	FORMAT=BMP
CAT	FORMAT=CAT
	COMPRESS=G3FAX	sets compression to FAX CCITT Group 3 for monochrome black-and-white images (depth of 1) only.
	COMPRESS=G4FAX	sets compression to FAX CCITT Group4 for monochrome black-and-white images (depth of 1) only.
	DESC=	enables description for catalog description.
DIB	FORMAT=DIB	is supported only by Windows 3.1, Windows 95, Windows 98, Windows 2000, and Windows NT.
EMF	FORMAT=EMF	is supported only by Windows 95, Windows 98, Windows 2000, and Windows NT.
EPSI	FORMAT=EPSI
GIF	FORMAT=GIF
JFIF	FORMAT=JFIF	is required for writing JPEG files that use JPEG File Interchange Format (JFIF).
	DCT=mode	selects the specific type of Discrete Cosine Transform (DCT) to use when processing the image; mode can be INT -- an integer DCT FAST -- a faster and less accurate integer DCT FLOAT -- a slightly more accurate method that can be slower unless the host has very fast floating-point hardware.
	GRAYSCALE	produces a gray-scale image even if the JPEG file is in color. This is useful for viewing on monochrome displays. The writer runs noticeably faster in this mode.
	VERSION	prints the version number and copyright messages for the Independent JPE Group's JFIF software to the log.
	FAST	enables certain recommended processing options for fast, low quality output; equivalent to enabling ONEPASS, DITHER=ORDERED, COLORS=216, NOSMOOTH, and DCT=FAST.
	NOSMOOTH	uses a faster, lower quality, upsampling routine.
	ONEPASS	uses a one-pass color quantization instead of the standard two-pass quantization. The one-pass method is faster and needs less memory, but it produces a lower-quality image. This attribute is ignored unless you also specify the COLORS attribute. ONEPASS is always enabled for gray-scale output.
	COLORS=n	reduces the number of colors in the image to at most n colors; n must be in the range 2...256.
	SCALE_RATIO=n	scales the output image by a factor of 1/n. Currently the scale factor must be 1/1, 1/2, 1/4, or 1/8. This is useful when processing a large image and only a smaller version is needed, because the reader is much faster when scaling down the output.
	DITHER=mode	selects the specific type of dithering to use color quantization; mode can be FS -- Floyd-Steinberg dithering ORDERED -- ordered dithering NONE -- no dithering.
PBM	FORMAT=PBM
	COMPRESS=NONE	creates a text PBM file.
	COMPRESS=BINARY \| RAW	creates a PBM file of reduced size by packing the pixels as binary data (this option is the default setting when FORMAT=PBM is specified)
PCL	FORMAT=PCL
	DPI=num	specifies the number of dots per inch to be used in the output file.
	EPS	does not reset the printer margins; use to embed an image into another PCL document.
PNG	FORMAT=PNG
PS	FORMAT=PS
	COMPRESS=NONE	is the default for color images.
	COMPRESS=RLE	sets compression to run-length encoded; default for gray-scale images. Also works with colormapped (256 color) images or RGB (millions of colors) images.
	DPI=num	specifies the number of dots per inch to use to calculate the visual size of the image on the PostScript page in the output file. The default is 300. For example, a 600-pixel by 600-pixel image appears as a 2-inch by 2-inch image on a PostScript page if you use the default setting.
	EPS	does not reset the printer margins; used to embed an image in another PCL document.
	PREVIEW	specifies whether a scaled-down, 1-bit, black-and-white preview image is written into the encapsulation header. The preview image enables this file to be read by software (such as SAS) that doesn't support a real PostScript reader.
	PREWIDTH=x PREHEIGHT=y	sets the size of the preview image in pixels. if PREVIEW is specified (default: 25% of original size).
	XSCALE	directly sets width scaling in points (1/72 inch). Default: calculate it.
	YSCALE	directly sets height scaling in points (1/72 inch). Default: calculate it.
	PAGEX	sets the output page width in points (1/72 inch). Default: 612 (a typical 8.5-inch page).
	PAGEY	sets the output page height in points (1/72 inch). Default: 792 (a typical 11-inch page).
	NOFIT	turns off the default of scaling an oversized image down to fit the page. Must be used with XSCALE and YSCALE. This option will be replaced by PAGEFIT in releases of SAS after 9.1.
	PAGEFIT	0 = Image size is not adjusted. 1 = Adjust the image size only of the image exceeds the page size (default). 2 = Always adjust the image size to fill the page. The PAGEFIT option replaces the NOFIT option in SAS releases after 9.1.
TIFF	FORMAT=TIFF
	COMPRESS=NONE	is the default.
	COMPRESS=G3FAX	sets compression to FAX CCITT Group 3 for monochrome black-and-white (depth of 1) images only.
	COMPRESS=G4FAX	sets compression to FAX CCITT Group 4 for monochrome black-and-white (depth of 1) images only.
WMF	FORMAT=WMF	is supported only under Windows operating systems.
XBM	FORMAT=XBM	is supported for writing only from interactive windows under UNIX.
XPM	FORMAT=XPM	is supported only under the X Windows System under UNIX.

Top of Page