[AlternaTIFF :: FAQ]

AlternaTIFF Frequently Asked Questions

Please read this carefully before asking for help:

Installation and registration

General questions

Questions specific to Internet Explorer

Questions specific to Netscape or Mozilla-based browsers

Questions from developers

How can I get technical support for AlternaTIFF?

The free version of AlternaTIFF is provided "AS IS," and has no official technical support. However, time permitting, we will usually respond to reasonable requests for help sent to via email to alternatiff@alternatiff.com -- but please search through the questions in this FAQ first. You are unlikely to receive a reply if you ask a question that is addressed here.

For best results, tell exactly what steps you took, what you saw, and how that differs from what you expected to see. Include the full text of any error messages (including the titles of message boxes), and any steps you took to try to fix it.

Tell us what web browser and web browser version you are using, and what version of AlternaTIFF you are using.

If you have a problem at a particular web site, we need to know whether it is limited to that web site, so please visit our test page and tell us whether that works. Include the URL of the web site if possible. If the web site is not freely and anonymously available to the public, we are unlikely to be able to help. Even if we can identify the problem, be aware that in most cases only the owner of the web site will be able to fix it.

If you have a problem with a particular image, include a URL where the image may be seen, or email us a copy of the image itself. If you cannot give us a copy of the image, at least include a copy of the information in the About box (right-click on AlternaTIFF -> About -> Copy Text, and paste into your email).

Questions should be in the English language. Sorry, we cannot respond to requests for support via telephone, or any method other than email.

Note that some of the more technical features of AlternaTIFF are documented on the technical documentation page.

Installation and registration

I installed it, but it doesn't work.

We're sorry to hear that, but we can't even begin to help unless you provide some details. See the previous question for tips on writing a meaningful problem report.

How do I get a "registration code"?

There should be no need to ever type in a registration code, or even know what it is. Note that you must download or install AlternaTIFF before you can register it.

If you still want to know your registration code for some reason, the "Manual registration" function will tell you to go to a web page at a location that looks something like this:

    http://www.alternatiff.com/register/?1234ABCD

The registration code is the 8-character string at the end of the URL ("1234ABCD" in this example), but if you go to that web page as directed, the form will automatically be filled out with that code.

Can you send me a registration code?

No, that isn't possible, and anyway you already have one, and there's no way for you to easily change it. You probably meant to ask for an activation key.

Okay, then can you send me an activation key?

Sorry, no. If and only if you include the URL that the "Manual Registration" feature told you to visit, then it would be possible for us to send back an activation key -- but it is not our policy to do that. If you do not have any internet access whatsoever, yet have somehow managed to acquire a copy of AlternaTIFF and this FAQ, we can only suggest that you ask a friend who does have internet access to do the registration for you, and tell you the activation key.

How can I register AlternaTIFF on a computer that does not have Internet access?

Use Manual Registration, copy down the web address that it tells you to visit, use a computer that does have Internet access to go to that address, and fill out the form. You will be given an activation key; copy it back into the original computer.

But that might be inconvenient for some people!

Yes, we know. (See also the next question.)

Do you have site licenses available so I don't have to manually register it on all my computers?

Yes, you can purchase site licenses that don't require additional registration.

How do I uninstall?

See the documentation.

Is there, or will there be, a Macintosh (or Unix/Linux) version of AlternaTIFF?

AlternaTIFF is only for Win32-based operating systems (Windows 95 and higher). No other versions are likely in the foreseeable future. The program is very Windows-centric, and porting it would not be easy.

The only TIFF plug-ins for Macintosh that we are currently aware of are Accel ViewTIFF and QuickTime, but there are probably others. It has also been suggested that the "Preview" application (included with some versions of OS X) may be useful in some cases.

Where is the auto-installed ActiveX control located on my computer?

You can list and manage your auto-installed ActiveX controls by going to Internet Options -> ["Browsing history" or "Temporary Internet Files"] Settings -> View Objects.

If you have a new enough version of IE, you can also use its "Tools" -> "Manage Add-ons" -> "Enable or Disable Add-ons" feature.

Typically, Internet Explorer stores things like this in the "Downloaded Program Files" subfolder of your WINDOWS or WINNT folder. You can also try searching your hard disk for a file named alttiff.ocx, but be warned that Microsoft's file search utility may skip files in your "Downloaded Program Files" folder, so you still have to look there manually.

If AlternaTIFF is working, you can find out exactly where it is by using it to view an image, right-clicking on the image, selecting "About" from the menu, and looking at the line that begins with "Location:".

Can I use AlternaTIFF to view email attachments?

Probably, but it depends on your email application, and we can't offer much help with that. It's hard enough just getting the major web browsers to behave themselves. With email applications, there are additional complications, including:

If you are using a third-party service which sends you TIFF files by email, and are having problems viewing their attachments, please try to get help from the owner of that service, rather than us (even if they specifically recommend using AlternaTIFF).

General questions

Why can I only view the first page of a multi-page document?

Because the TIFF file you are viewing contains only a single page. AlternaTIFF can display (or print, or save) multiple pages if and only if the TIFF file contains multiple pages. Some web sites, such as the USPTO site, present multi-page documents as many separate single-page TIFF files, rather than a single multi-page TIFF file, so AlternaTIFF's multi-page features cannot be used.

The only solutions are for the web site to change its ways and start offering multi-page TIFF files, or for someone to write a special utility to automate the process of downloading and combining files from that particular web site. Because every web site is different, it's not possible to write a single utility that will work for all web sites. Also, be aware that some web sites have an Acceptable Use Policy that forbids this type of automation.

Some people have written special utilities for the USPTO site; see PatentMailer or pat2pdf or innoVUE/interneTIFF. There are also services like US Patent Search and GetThePatent. (Please note that we have no affiliation with any of the products or services listed here -- this is not an endorsement.)

Why can I only print one page of a multi-page document?

If this is in regard to the U.S. Patent Office site, look here.

Right-click on the image and choose "About" from the menu. If it says "Number of pages: 1", then the reason is that the TIFF file only has one page.

If the file does have more than one page, the most likely reason is that you're using your web browser's Print function, rather than AlternaTIFF's. Using the web browser's Print function will only print what is currently visible on the web page.

Why can I only save one page of a multi-page document?

If this is in regard to the U.S. Patent Office site, look here.

Right-click on the image and choose "About" from the menu. If it says "Number of pages: 1", then the reason is that the TIFF file only has one page.

If the TIFF file does have more than one page, then maybe you're saving to BMP format (which only supports one page), or maybe the file contains some unusual type of image (such as a thumbnail or sub-IFD) which might not be displayed by other applications.

A particular image always gives an error that says something about 'decode' or 'strip' or 'bytes expected' or something similar.

This means that the TIFF image you are trying to view is invalid or corrupt, or at least that's what AlternaTIFF thinks. The image cannot be displayed by AlternaTIFF.

You can still use AlternaTIFF's Save As TIFF function even if the image could not be displayed. Try saving it to disk, then opening it with some other image-viewing programs, to see if they can read it.

If you send us a copy of the file, we'll take a look at it. However, errors like this are generated by the libtiff library, which was not written by us, so it may be difficult for us to do anything about it, even if we think that the file is actually valid.

I get an error that says "... unsupported compression method" or "... compression support is not configured."

TIFF images can be compressed using any of a number of different compression algorithms, and AlternaTIFF does not support all of them. This error means that the image you are trying to view uses a compression algorithm that is not supported by AlternaTIFF. You will not be able to use AlternaTIFF to view this image. You can still save the file to disk, and then use some other graphics program to view it.

If the compression algorithm is "Old Style JPEG", make sure you're using AlternaTIFF version 1.8.0 or higher.

The toolbar's gone! How do I get it back?

Right-click on a TIFF image while it is being displayed in your browser, choose "More Settings" from the menu, set "Default toolbar position" to "Top", and click OK.

If you don't get a menu, or you get a menu with no "More Settings" option, then you are apparently not using AlternaTIFF (which would explain the absence of the AlternaTIFF toolbar). Maybe QuickTime is interfering?

Web pages can temporarily override your toolbar setting. Other than that, the toolbar should never disappear unless you turn it off.

Why do I get a "Not a TIFF file" error?

Well, it means what it says. The file that AlternaTIFF has been asked to display is not in TIFF format, and therefore cannot be processed by AlternaTIFF. The most common reason for this is that the file is actually some sort of error document generated by the web server, such as a "404 Not Found" page.

Starting with version 1.6.5, AlternaTIFF attempts to display the textual contents of non-TIFF files as part of the error message. It may not look pretty, but it may provide a clue as to what the problem is.

You might also try right-clicking on AlternaTIFF and selecting "View Image". This will allow your web browser to try to process the document directly. Or, if you're technically-inclined, you could save the document to disk, and then try to figure out what it really is.

I get a "Waiting for download to start..." message.

That's the status message displayed by AlternaTIFF after it has requested the TIFF document from the web browser (and, indirectly, the web site), but before it has received any response to that request. If it appears for longer than a fraction of a second, and your computer isn't busy downloading other things, then something's probably gone wrong.

If the problem occurs on just one web site, there's probably something wrong with that web site. If it occurs on all web sites, there must be something preventing TIFF documents from reaching you, such as a firewall, proxy server, ad-blocker or other filtering software. In either case, you could try right-clicking on the message, and selecting "View Image" from the menu. With any luck, you'll get an error page giving some information about what went wrong.

Error: "Browser sent too much data for image" or "Inconsistent amount of data received".

This error means that inconsistent file-size information was received by AlternaTIFF (most likely caused by an incorrect Content-Length HTTP header). It probably indicates that a web server malfunction caused the TIFF file to be corrupted. The problem needs to be fixed by the web server operator or web application developer.

QuickTime runs instead of AlternaTIFF.

Unless you configure it not to, QuickTime may register itself as your TIFF file viewer, thus disabling AlternaTIFF.

The following instructions describe how to configure QuickTime to not handle TIFF files. Note that some versions of QuickTime are slightly different. Very old versions (before 4.1) are very different, and you might consider upgrading or uninstalling.

  1. From the Start menu, select "Control Panel".
  2. [Windows XP] If it says "Pick a category", click "Switch to Classic View" at the upper-left.
  3. Double-click the "QuickTime" icon.
  4. Click the "Browser" tab, or from the drop-down list, select "Browser Plug-in". Click the "MIME Settings" button.
  5. Double-click the "Images ..." item to expand it.
  6. If the "TIFF ..." or "image/tiff" item is checked, uncheck it.
  7. Press the "OK" button, then close the "QuickTime Settings" window.

If you've already installed that ActiveX version of AlternaTIFF, and that doesn't re-enable it, proceed to this question.

If you're using Netscape or a Mozilla-based browser, and having trouble disabling QuickTime, this item may also be useful.

If you have a problem with QuickTime that this does not resolve, check with Apple for support options.

Unable to print extremely large images.

If you print an extrememly large image (say, over 10,000 pixels wide or tall), you may sometimes only get a blank page.

There are limits to the image size that AlternaTIFF (and the Windows features it uses) can handle, and as images get larger, often the first thing to fail is printing. The exact limit depends on what your printer driver software can handle. Unfortunately, there is no workaround at this time. You'll have to open the image in a more advanced graphics application, and print from there.

Does AlternaTIFF have keyboard support?

AlternaTIFF has very little keyboard support. For a variety of reasons, keyboard handling is problematical in plug-ins and similar web page objects. It's very difficult to sort out which keystrokes should be handled by which object. Plus, no matter what key commands we choose, someone is bound to find them objectionable because they conflict with their application that uses AlternaTIFF.

Here are the only keyboard commands available. However, in most circumstances these will not work in Internet Explorer.


IE normally reserves navigational keys for itself, so these keys do not work in IE except in full-page mode (which has its own problems). (It is possible for an ActiveX control to dig around in IE and intercept its keystrokes, but for now at least, we have chosen not to do that.) In most other browsers, the keys will work even in embedded mode, but you may have to first click on the plug-in (or perhaps Tab to it) to set keyboard focus.

Here's another idea: If you are the author of a web page that uses AlternaTIFF in embedded mode, note that most browsers make it possible to read keystrokes using JavaScript (or VBScript, whatever). The script can then turn around and send commands to AlternaTIFF (here's a demo). So if AlternaTIFF supports the commands you need, you can write your own keyboard handler that works just the way you want.

Does AlternaTIFF have (some feature)?

If you don't see it on the menu, probably not. Before you ask, here are some features that AlternaTIFF does not have:

How do I view TIFF files after I've saved them to my computer?

AlternaTIFF is designed and optimized for viewing TIFF files on the web, and not for viewing files that are already on your computer. We suggest using a general-purpose image viewer, rather than AlternaTIFF. But we recognize that, for consistency and other reasons, some people would still prefer to use AlternaTIFF for viewing local TIFF files.

Probably what you want to do is to browse to a TIFF file using Windows Explorer or My Computer, double-click on the TIFF file, and have it open up in AlternaTIFF. The way to do that is to associate ".tif" files with your web browser. (However, there may be a problem with Windows XP; see below.)

How do you associate files? The way to do it is slightly different in every version of Windows (search Windows Help for "associate file", or search the web). Here's a method that usually works:

  1. Use Windows Explorer or My Computer to locate any TIFF file on your computer, and select it (left-click).
  2. Hold down the Shift key while you right-click on it, then choose "Open With" from the menu. (With Windows XP, right-click -> "Open With" -> "Choose Program...")
  3. Select your web browser (e.g. Internet Explorer) from the list, or if it's not listed, press "Other" or "Browse" to locate it.
  4. Make sure "Always use ..." is checked, then press "OK".

Internet Explorer (Windows XP SP2 and newer), may give you security warning before allowing ActiveX controls to run in the "My Computer" zone. To turn off the warning, go to Internet Options -> Advanced -> scroll down to the Security section and check the Allow active content to run in files on My Computer setting (or the setting about CDs, if your files are on a CD). Be aware that doing this disables a security precaution, and may potentially allow security flaws in IE to be more easily exploited. It can also cause the problem described here.

On Windows XP, that may not be sufficient, because XP has built-in imaging features that can interfere. Apparently, it works on some computers, but not others. Unfortunately, at this time we don't know of any good solution.

The only reliable solution that we know of isn't a very good one: completely disable XP's built-in imaging features. This can be done with [ Start -> Run -> "regsvr32 /u shimgvw.dll" ]. (To re-enable, enter the same command without the "/u".) Do this AT YOUR OWN RISK. Consider backing up your System State data (registry) first. It appears to be relatively safe, but it will disable some things, and we can't guarantee that re-enabling it will put everything back exactly as it was before.

Problems viewing patents at the US Patent and Trademark Office (USPTO)

*** Please note that we are not affiliated with the Patent Office web site in any way ***

If the problem is that you can only view or print one page at a time, read this.

Otherwise, please verify that the problem is specific to the Patent Office site by visiting our test pages. If it does not work there, this question does not apply to you, and you could start by reading this.

Historically, this site has caused problems for Internet Explorer, but that mostly seems to be a thing of the past. If you're using an old version of IE (older than 6.0), we suggest upgrading.

If you're having a problem only at the USPTO site, and you're reasonably sure that it's not just a temporary web site outage, consider reporting it to us.

Other options:

Problems viewing documents at Origins Network web sites

*** Please note that we are not affiliated with Origins Network in any way ***

Please verify that the problem is specific to the Origins site by visiting our test pages. If it does not work there, this question does not apply to you, and you could start by reading this.

We receive a number of reports of problems at Origins Network (British Origins, Irish Origins, etc.). Presumably, that is in part simply because they are a large subscription-based site, and people are much more likely to report problems if they paid for access.

We do not usually have access to this site, so we are unable to diagnose problems with it (unless you can provide an extraordinarily detailed and technical description of the problem). Even if we could, we would probably not be able to do anything about it. Once you've verified that AlternaTIFF does work on sites other than Origins, we suggest contacting Origins Network's support personnel instead of us.

Questions specific to Internet Explorer

It doesn't work in IE

Sometimes, instead of loading AlternaTIFF, IE may just display a rectangle with an icon similar to one of the following:
[screen shot] or [screen shot]
Clicking on it may or may not produce an error message of some sort.

(Some web pages, such as our installation page, provide alternate content to be used in the event that an ActiveX control could not be used. In that case, you may see a message, maybe something like "You need to install a TIFF viewer", instead of a rectange-with-icon.)

If AlternaTIFF used to work, but no longer does, read this.

Please check whether it works at our test page. If all of the tests are successful, then it is installed correctly, and there is probably a problem with the web site you're using, not with AlternaTIFF. If only Test 3 is unsuccessful, read this.

If the problem is only with the US Patent Office site, read this. If the problem is only with some other public web site, we're usually willing to help diagnose problems like that if you email us the URL of the site. Sorry, but we can't help with problems on web sites that aren't accessible to us.

If you are not the system administrator of your computer, this would probably be a good time to ask your system administrator for help.

Microsoft has an article that tells how to identify problems downloading ActiveX controls. It's somewhat technical, but it may be the only direct way to identify the problem. AlternaTIFF's ClassID (CLSID) is listed here.

If using Windows NT or 2000 or XP, make sure you have permission to install and run ActiveX controls on your computer. Ask your system administrator, or log in as a more privileged user.

Make sure you are not behind a firewall or proxy server that intentionally blocks ActiveX downloads or TIFF files. If you use a download manager, "safe surf" utility, or any similar type of browser add-on, try disabling it.

Make sure your IE security settings allow you to install and run ActiveX controls (usually configured in Tools -> Internet Options -> Security -> Internet). This is a long shot, because IE will usually tell you when that is the problem.

Try to install it again from the auto-install page. If the "AlternaTIFF ActiveX control is installed in your browser" image shows up, but it still doesn't work on our test page, try re-activating it.

IE7 has a feature to reset all settings: Tools -> Internet Options -> Advanced -> "Reset...". This is a fairly drastic step, and will probably reset some things that you don't really want to reset. However, it has been known to fix some ActiveX problems that are otherwise nearly hopeless to fix.

For advanced users: In some cases, manually installing from the ZIP file (option 2 on our front page) may succeed even if auto-install fails. We advise against this unless the download completely failed -- it won't help with any other type of problem.

If none of the above suggestions help, sorry, but you may be out of luck. AlternaTIFF does everything it can to try to convince IE to use it, but we still get a few reports that it does not work in some copies of IE. Unless you have some idea of what may be causing the problem, or you can tell us how to reproduce the problem on our own computers, we probably aren't going to be able to help. We can only suggest that you seek help from an Internet Explorer expert or support forum, or use a different web browser (such as Firefox) when you need to visit web sites that use TIFF images.

It doesn't work in IE: I get a red X icon

Sometimes, IE may show a red X icon similar to this:

Some of the problems listed above can result in a red X icon.

Additionally, and especially if you installed from the ZIP file, a red X may mean that IE was unable to access AlternaTIFF's main alttiff.ocx file. Either the file is no longer present (in its original location), or the current user does not have sufficient permission to use it. For example, you may have placed the file on a mapped network drive that is no longer present. Or, you may have installed it multiple times in different locations, and then deleted the wrong copy. Reinstalling it in an accessible location should fix it.

It is important to know that the install.bat script included with the ZIP file version does not actually copy any files. Basically all it does is to record the location of alttiff.ocx, so that IE can find it.

The ActiveX version used to work, but now it doesn't.

Most likely, something has changed some of your Windows registry settings concerning TIFF files. Internet Explorer is very picky, and can stop working right if even the slightest change is made.

If you installed it from the ZIP package, it should be sufficient to reinstall it by running install.bat.

If you used the auto-install method, you may find that AlternaTIFF works on the install page but nowhere else. If that's what happens, go to this page to try to re-activate it. (Or you could do it the hard way, by uninstalling and then reinstalling it.)

If AlternaTIFF repeatedly stops working, you may have to play detective to try to figure out what it is that's disabling it. Does it only happen after you run a certain application (such as QuickTime)? Or only when you reboot? Or at a certain time of day? Or when something has been updated? Find the pattern.

If you are an administrator investigating this type of problem, this list of registry settings might be of use.

Images print compressed into the left part of the page.

When printing using IE's Print function (Print button, Print menu item, Ctrl+P, etc.), some TIFF images may be strangely compressed into the left part or top part of the page, or of the region where they are supposed to print.

This is caused by a design flaw in Internet Explorer. It creates print images of ActiveX controls before you even select a printer to print to, which makes it impossible for an ActiveX control to reliably determine the correct height-width ratio to print at. The problem occurs in two situations:

1. When the web page uses percentages, rather than pixels, to size the TIFF image.
In this case, we suggest one of the following:

2. When viewing the TIFF image directly, so that it takes up the entire browser window.
You can avoid this problem by using AlternaTIFF's Print button instead of IE's. You could also try turning on the "Stretch to Fill Print Region" option described above, but that will not necessarily print the image correctly, and it will still print IE's headers, and will still only print the current page. (We believe that in this case it may be technically possible for an ActiveX control to work around the problem completely, by somehow intercepting IE's Print function, but current versions of AlternaTIFF do not have that capability.)

I see the message "Click to activate and use this control" (or: "I have to click the Print button twice").

This is due to an intentional change made to Internet Explorer in an April 2006 patch, and it applies to all ActiveX controls. Microsoft was forced to do this because of a lawsuit relating to a patent on the concept of interactive web browser plug-ins that run automatically. There is necessarily no simple way for the user to work around this inconvenience. It is possible for the web site owner to work around it, however.

See http://www.microsoft.com/technet/security/advisory/912945.mspx and http://support.microsoft.com/kb/912945.

Full-page mode doesn't work in IE6

Starting in late 2007, we've been receiving sporadic reports of IE6 refusing to use AlternaTIFF in full-page mode. The symptom is that Test 3 does not work on our test page, but Tests 1 and 2 do.

At this time, we have almost no information about this problem, except that it does not seem to be the same as the IE7 problem. We have not been able to reproduce the problem ourselves. We have received no reports of anyone finding a way to fix it (except by switching to a browser other than IE6). Since AlternaTIFF has not changed, it's a reasonable guess that this was caused by one of Microsoft's updates to IE. If you have any further information about this problem, we'd appreciate hearing from you.

Full-page mode doesn't work in IE7

If you have enabled the "Allow active content to run in files on My Computer" Internet setting, full-page ActiveX controls (such as Test 3 on our test page) probably won't work in IE7. You'll just get a blank white rectangle, possibly with some Script Errors about "Invalid character" or "Object expected".

This is caused by a defect in IE7's security features. If you need to use IE at a site that uses full-page TIFF files, here are some possible workarounds:

We have received reports that this problem, or a similar one, also exists with IE6 in Windows Server 2003 with SP2.

Installing updates from Microsoft disables AlternaTIFF.

As reported by several users, installing certain updates from Microsoft may cause your computer to be reconfigured such that IE will no longer use AlternaTIFF to handle TIFF files.

Unfortunately, we don't know the exact circumstances in which this problem occurs, or how to prevent it. (Maybe it is limited to Microsoft Office updates?) If you can help us to reproduce it, or identify the specific changes that are disabling AlternaTIFF (refer to this list of registry settings), we'd appreciate hearing from you.

Presumably, after this happens, you can reactivate AlternaTIFF to make it work again.

Questions specific to Netscape or Mozilla-based browsers

Browser won't load the plug-in; it only displays a rectangle with a picture of a puzzle piece.

Possibilities:

Another plug-in loads instead of AlternaTIFF.

Note: This item mentions DLL files, which some versions of Windows keep hidden by default. To manipulate DLL files, you may need to go into Folder Options (from Control Panel or My Computer) and turn on the "Show hidden files and folders" setting, and turn off the "Hide extensions for known file types" setting.

If you have more than one plug-in installed that can display TIFF files, your browser may just pick one of them, seemingly at random. Some of the newer web browsers have a way to manually select the plug-in to handle TIFF files, such as at Tools -> Options -> Content -> [File Types] Manage. Try that first if it's available.

If your web browser does not have a convenient way to select the plug-in to use, read on.

If you don't recognize the plug-in being used: Most plug-ins can be identified by right-clicking on the image, and if you get a menu, maybe the "About" item or some other item will help. If that doesn't work, choose Help|About Plug-ins from the menu, or if there is no such item, type "about:plugins" into the location bar and press Enter. Search the list for plug-ins that support a MIME type of "image/tiff".

QuickTime only: Apple's QuickTime plug-in is the most common problem here, and it is also a special case, because it has the ability to configure exactly which file types to support. Please read our information about disabling QuickTime's TIFF support. If that doesn't work, it's probably because you have extra "stray" copies of QuickTime plug-ins lying around, so follow the instructions below for locating and disabling plug-in files.

If you don't have any use for the conflicting plug-in, simply uninstall it. If you can't find an uninstall program for it, follow the instructions below for locating and disabling plug-in files.

On the other hand, if you need to keep using the conflicting plug-in for other file types, skip to the "changing plug-in priorities" section below.

Locating and disabling plug-in files:
Choose Help|About Plug-ins from the browser's menu, or if there is no such item, type "about:plugins" into the location bar and press Enter. You should see a list of your plug-ins. Find the plug-in that you want to disable, and note what it says for the file name.

If the file name does not contain a full path; e.g. if it is something short like "npqtplugin.dll" instead of something long like "C:\Program Files\Mozilla Firefox\plugins\npqtplugin.dll", then do the following. Enter "about:config" into the location bar, find the item named "plugin.expose_full_path", double-click on it, and change the value from "false" to "true". Then repeat the About Plug-ins step.

When you've figured out the full name of the plug-in file, locate it in My Computer or Windows Explorer, and rename it so it ends with ".old" or anything other than ".dll". Restart your browser, and if that didn't fix it, go back to the About Plug-ins step and repeat.

Changing plug-in prorities:
Assuming you need to continue to use the conflicting plug-in to view other types of files, then the problem is more difficult. There is at least one commercial solution: the Plugsy plug-in manager.

If you're using Windows 95/98/ME (or maybe an upgraded-to-XP installation?), here's another possibility, if you're desperate: Move all the files out of your Plugins folder, and then move them all back in reverse order of desired priority (npzzatif.dll should be last). This can work because plug-in precedence is sometimes determined by the order that the files appear in the Plugins folder. (Use "DIR /-O" from a DOS prompt to see the current order.) (However, your plug-ins may not all be in the Plugins folder -- more investigation is needed here.)

In Netscape 6 or 7, displaying a TIFF image on a page by itself doesn't work right.

When you go directly to a ".tif" URL with some versions of Netscape, it may do one or more of the following:

These problems are all caused by bugs in Netscape. If you're a web author and can't live with these bugs, a possible workaround is to serve the files with a MIME type of "application/x-alternatiff" or "image/x-tiff" rather than "image/tiff".

Questions from developers

How do I embed TIFF images into my web pages?

It depends on what web browsers you're trying to support, and your tolerance for nonstandard and/or bloated HTML. Here are a few suggestions.

What are AlternaTIFF's file types and identifiers?

MIME types: image/tiff, image/x-tiff, application/x-alternatiff
File extensions: .tif, .tiff, .alttif
CLSID: {106E49CF-797A-11D2-81A2-00E02C015623} (ActiveX version only)
ProgID: Alttiff.AlttiffCtl (ActiveX version only)

Problems viewing TIFF files directly, without embedding in a web page

This applies to:

If you try any of these things in IE, you may encounter problems. Usually it does work, but sometimes IE may just display a blank page, or an error message, or a file-download dialog. In some cases, the TIFF file will be downloaded twice from the server. It may not work if the TIFF file was generated as the result of a form POST. It may not work if the URL contains certain unusual characters, such as a single-quote. If the TIFF file contains a lot of data that could be interpreted as plain text, IE may treat it as a plain text file. IE may display an incorrect warning about the page containing "both secure and nonsecure items". There may be problems with client-side scripting. In IE7, it conflicts with a seemingly-unrelated Internet setting. In some copies of IE6, it reportedly doesn't work at all. And there are undoubtedly other problems, not listed here.

The fact of the matter is, full-page ActiveX controls just don't work very well in IE. Support for them seems to have been an afterthought by Microsoft, and IE's ActiveX interface was not really designed correctly to handle them. AlternaTIFF supports them about as well as it can, but if you can avoid relying on this, we recommend you do so. If you decide you need full-page viewing, we suggest you at least:

If you're getting a file-download dialog, and for whatever reason you can't fix the server, here's a bit of magic that might help. Create the following registry key on the client's computer:
HKCR\CLSID\{106E49CF-797A-11D2-81A2-00E02C015623}\EnableFullPage\MIME\image/tiff
This will cause IE to be more likely to use AlternaTIFF in full-page mode. Unfortunately, it also causes new problems with embedded TIFF images -- note that some of the examples on our How To Embed page will no longer work.

Can I use the ActiveX control in my own program (without using Internet Explorer)?

This is not strictly forbidden, but the practical answer is "probably not." (Or at least, not unless you use it via Microsoft's WebBrowser ActiveX control -- but that's really Internet Explorer.) The ActiveX version of AlternaTIFF is intended for use only in Internet Explorer, and other hypothetical web browsers that support the same ActiveX interface. If you want to use it in some other application, it's up to you to figure out how to do it -- we haven't added any interfaces to make it easy, so your program will have to closely emulate IE's environment. And you're not allowed to circumvent the registration requirement, or to try to make it look like AlternaTIFF is an integral part of your own software.

Here's a list of scripting methods, but you will find that there's no easy way to open an image file.

Is AlternaTIFF scriptable (using JavaScript or VBScript)?

Some client-side scripting features are available in the ActiveX version starting with version 1.5.0, and in the plug-in version starting with version 1.5.2.

How do I detect if the visitor has AlternaTIFF installed?

The same way you detect any other plug-in or ActiveX control. Unfortunately, there is no perfect way to detect a plug-in or ActiveX control. There may or may not be a way to do it that works well enough to satisfy your particular needs. This question is somewhat beyond our expertise, so we recommend searching the web, or asking in a support forum for web developers.

The following is a quick and dirty example of one way to attempt to load an ActiveX control and detect whether it succeeded. This is just an example, and is not the only way, or the best way, to do it.

<script type="text/vbscript" language=VBScript>
  On Error Resume Next
  detected = IsObject(CreateObject("Alttiff.AlttiffCtl"))
  If detected Then
    MsgBox "Detected."
  Else
    MsgBox "Not detected."
  End If
</script>
May I put a link to your web site on my web site?

Yes, of course. Though we do ask that you not link directly to documents that aren't web pages, such as CAB, ZIP, EXE or image files. If you want to bypass our web pages, we'd prefer that you place copies of the distribution files on your own server.

And if you're going to recommend AlternaTIFF for use on your web site, we'd appreciate it if you'd ensure that your web site works reliably with AlternaTIFF. In particular, please be aware of the pitfalls of full-page ActiveX controls, if your site uses them.

How can I create TIFF files that contain multiple images?

Use computer software that has that capability. A few examples:

Where can I get more information about the TIFF file format?

Can you recommend a program to do (something)?

Sorry, but probably not. We're not trying to keep anything from you, but we don't have the time or the inclination to do the ongoing research necessary to make good recommendations about other imaging software. We suggest you try to find an appropriate discussion group or mailing list, and ask there.