Accel ViewTIFF Specification

Accel ViewTIFF is a Windows or MacOS compatible plug-in/Active X control for image-enabling Internet Firefox, Opera, and compatible web browsers. With Accel ViewTIFF, every Windows or MacOS client can quickly view images efficiently stored in large TIFF file archives.

OS Supported

Windows 7/VISTA/XP/2000/98/NT
Macintosh OS X 10.5 and above   (see the Download page for info on older OS X)

User Features

When you display an image, you will find a pop-up menu by clicking and holding any spot on the image itself. Try all the functions. Compare the speed to any other image display on any platform! We're confident that you'll be impressed.

Accel ViewTIFF's on-image menu lets you modify the default image size and rotation. Just view an image the way you want your default to look, then pick "Save settings" in the on-image menu.

Feature list:

• Enlarge or reduce the image size, or zoom to fit image area on web page. Zoom level is governed by enlarge/reduce controls, Zoom cursor rectangle and Zoom menu. The mouse-click point is the center for the new image view. Zoom settings (percentages are for a 200 dpi image) are: 1:1 (300%) 1.5:1 (200%) 2:1 (140%), 2.25:1 (125%), 2.5:1 (110%), 2.8:1(100%), 3:1 (90%) , 3.5:1(80%), 4:1(70%), 5:1(50%), 6:1(40%), 8:1(35%) or zoom to fit image area on web page.
• Rotate: 90, 180, 270 degrees (at any zoom factor)
• Scale to gray: enable/disable
• Zoom to area
• Panning with cursor (hand cursor)
• Saved settings will be remembered on disk, defaults for the first use are:
  • Zoom to 100%
  • Scale to gray: enable
• Multpage TIFF support, page forward/back and goto page.
• Print command will print the TIFF document scaled to fit on one page. The page size as defined by the currently selected printer on the Macintosh. Printing will take advantage of the full resolution of the TIFF file for best clarity on paper.
  
• Saving file to local disk as a PDF.
• Saving file to clipboard.
• Saving a region of the file to the clipboard or as BitMap (Windows .BMP), or as PICT (MacOS).
• Automatic paging of single page TIFF files stored with a page number extension or with a page number argument in the URL query string.

Programmer Features

Your HTML files can invoke the Accel ViewTIFF Plug-in/Active X control to show Black &White TIFF Images in either of two ways: full frame or embed.

1. A full frame view is invoked with a command like

<A HREF="ImageName.tiff">full-frame TIFF image</A>

To display a full frame image using the file:// command, the file name must have a .tiff or .tif extension.

To display a full frame image using the http:// command, the MIME type must be sent from the web server. Refer to your web server documentation on how to set up MIME types.

Regardless of the methods used, the bottom line is that ViewTIFF will be invoked only if the web browser determines that the incoming file is a MIME type image/tiff.

2. The syntax of the EMBED tag is as follows:

<EMBED attributes>...</EMBED>

where standard attributes are:

SRC="filename"	Specifies the URL to the TIFF file. Files that have the extension ".tiff" or ".tif" will invoke the ViewTIFF plug-in if opened locally; the web server will determine the MIME type if the file is sent via http://.
TYPE="image/tiff"	Can be optionally used to invoke the ViewTIFF plug-in if the file name doesn't have the .tiff extension. Check the documentation for your web browser software for rules on the interpretation of the TYPE attribute. You can use the same methods for invoking ViewTIFF to display an embedded image as are described above for displaying a full frame image.
WIDTH=value	Defines the horizontal size in the units defined by the UNITS attribute (default is pixels).
HEIGHT=value	Defines the vertical size in the units defined by the UNITS attribute (default is pixels).
UNITS=value	Defines the measurement unit used by the HEIGHT and WIDTH attributes. The value can be either PIXELS (the default) or EN (half the point size).

The TIFF plug in specific attributes are:

ZOOM=value	Defines the zoom factor to use in percent, or if "FIT WIDTH" is specified the image is scaled to fit the width of the rectangle specified by HEIGHT and WIDTH (minus the scroll bars),or if "FIT HEIGHT" is specified the image is scaled to fit the height of the rectangle specified by HEIGHT and WIDTH (minus the scroll bars), or if "FIT" is specified the image is scaled to fit within both the width and height of the rectangle specified by HEIGHT and WIDTH (minus the scroll bars). The user's on-image enlarge/reduce menu sets scaling to: 1:1 (~400%) 2:1 (~200%) 3:1 (~125%) 4:1(~100%) 5:1(83%) 6:1(69%) 8:1(~50%) or zoom to fit image area on the browser page.
ROTATE=value	specifies the rotation angle in clockwise degrees. 0,90,180 and 270 are the only legal values, default is 0 degrees.
GRAY=value	specifies the image should be gray scaled if value = "YES", or not if value = "NO".
PAGE=value	specifies the page to show for multi-page TIFF documents, default is the first page.
PAGES=value	specifies the maximum page number for single-page TIFF documents using a page number extension or a page number argument to the URL query string. If omitted this is determined when the user pages beyond the end of the document.
HOFFSET=value	specifies the horizontal offset of the left side of the image in pixels, the image will be scrolled horizontally so this pixel (in image co-ordinates) is on the left hand side of the image area, default is 0 to show the left side of the image. If the value is greater than the image can be scrolled, then the image will be scrolled so as to show the right edge on the right side of the image area.
VOFFSET=value	specifies the vertical offset of the top edge of the image in pixels, the image will be scrolled vertically so this pixel (in image co-ordinates) is on the top edge of the image area, default is 0 to show the top of the image. If the value is greater than the image can be scrolled, then the image will be scrolled so as to show the bottom edge at the bottom of the image area.

TIFF Formats Supported:

TIFF documents compressed with the following are supported:

• CCITT Group 4
• CCITT Group 3 1-D and 2-D
• TIFF Mode 2 (a variation of CCITT Group 3)
• GIF Style Color, CompressionType 5 (Windows only)
• Packbits, CompressionType 32773 (Windows only)
• Uncompressed (Windows only)

Both Intel 'II' and Motorola 'MM' style byte ordering in the header are supported.

Bit ordering with the image data from high bit to low bit (TIFF Standard) is recommended. The TIFF Spec does provide a FillOrder tag for reverse bit ordering but recommends not to use reverse bit ordering or the tag. ViewTIFF does support this feature, but other TIFF viewers may not, so deploy with caution.

Tags Supported:

ImageWidth
ImageLength
BitsPerSample (must be 1 on MacOS - i.e. Black & White)
SamplesPerPixel (must be 1 on MacOS - i.e. Black & White)
Compression (types 1, 2, 3, 4)
StripOffset (may be multiple strips)
StripBytesCount
Group3Options (cannot support uncompressed mode)
Group4Options (cannot support uncompressed mode)
XResolution (resolution assumed to be dots per inch)
YResolution (resolution assumed to be dots per inch (may be approximately half X resolution for low res faxes)
FillOrder tag for reverse bit ordering

In addition on Windows Only:

All other tags will not produce an error, but will not be interpreted. Decompression will not begin before the whole TIFF file has arrived, so the header does not need to come first. Multi-page TIFF is supported.

Multi-page TIFF

Multi-page TIFF documents are supported. When a TIFF document with more than one page is used, the menu that is available by clicking on the document will show the following additional menu items: "Next Page", "Previous Page", and "Goto Page" (with a sub-menu of page numbers to go directly to a specific page). The maximum allowed pages in a TIFF document is 256 on Mac OS, unlimited on Windows. When switching from page to page, the zoom level, page rotation and gray scale attributes are kept the same. If the user interrupts the download of a multipage TIFF document, the pages which have already been downloaded will be available, but those not downloaded will be missing.

Paging Support with Single Page TIFF files

If the URL to the images ends in a page number extension (for example "-001.tif", ".01" or "_1.tiff"), or the query string contains a page number argument (for example - "&pagenum=","&page=", or "&pgnno=") then Accel ViewTIFF will display the page control toolbar and menu items allowing the user to automatically page through the document, print multiple pages and save multiple pages. Accel ViewTIFF will navigate to the subsequent pages automatically by changing the page number portion of the URL or the page number value in the URL query string.

Filename Page Number Extension

Accel ViewTIFF will do paging control if the filename ends in a 1 to 3 digit number that is preceded by a character in the set "-._/|;~". The filename can optionally have the extension ".tif" or ".tiff".

Query String Page Number Arguments

Accel ViewTIFF now automatically detects page numbers in file names or in CGI query strings and presents page controls for multipage operations with TIFF documents stored as separate pages.

Accel ViewTIFF will do paging control if the query string contains any of the following arguments:
"&pagenum=", "&pageno=", "&page=", "&pagen=", "&pgno=", "&pgnum=", "&pgn=", or "&pg=".

Memory Requirements:

The TIFF file and image are both held in memory at the same time. For example, at 300 dpi a 8.5" by 11" images takes 1032K (~1M). The TIFF file should be 100K on average. The plug-in will need about 1.3 MB all together.

Customization:

Contact us for a quote if you need enhancements or new features or even a custom plug-in/Active X Control for your documents.