[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 browsers other than Internet Explorer

Questions from developers and administrators

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 [email protected] -- 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:


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.

On what kinds of computers does AlternaTIFF work?

(Does it work on...)

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:".

Why does installation fail with error code 0x80070005?

0x80070005 is a Microsoft error code that means "access denied". The most common situation where you might see this error is if you are installing it manually (from the ZIP file), while running as a user who does not have permission to install software. It should work if run from an administrative command prompt, or while logged in as an administrator or power user.

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 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.

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

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?

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.

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.

Every other page fails with an error.

If each page of a multi-page document is followed by an extra undisplayable image and an "Unsupported samples/pixel" error, your TIFF file probably contains malformed thumbnail images created by Microsoft Office Document Scanning or a related application.

It's not possible for AlternaTIFF to display the thumbnails, but they are probably marked as "sub-IFD" and "reduced-size", so you can hide them by configuring AlternaTIFF to ignore one or both of those types of images: Right-click on an image -> "More Settings" -> "Advanced" -> "Ignore ...".

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 steps describe how to configure QuickTime to not handle TIFF files. Not all versions of QuickTime are the same, so these instructions may not be perfect.

  1. From the Start menu, select "Control Panel".
  2. Locate the QuickTime icon. It may be in a category like "Other". If "Classic View" is an option, it may be easier to find QuickTime from there.
  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. For that, we suggest using a general-purpose image viewer, rather than AlternaTIFF. But we recognize that, for various reasons, some people would like to use AlternaTIFF to view local TIFF files. There is nothing wrong with doing that, but our ability to help with problems will be limited.

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 a web browser into which AlternaTIFF has been installed.

There are several ways to associate files with programs, and they are slightly different in different versions of Windows. Try searching the Windows help system for a topic named something like "associate a file with a program".

For example, in Windows XP: locate any .tif file using Windows Explorer, right-click on it, select "Open With" -> "Choose Program" from the menu, select your web browser (or use the Browse button to locate it), check the "Always use..." checkbox, and press OK.

You may find that Internet Explorer requires you to click through a security warning for each file. To eliminate this warning, you can enable the "Allow active content to run in files on My Computer" security setting (in Internet Options -> Advanced). However, enabling this causes another problem: read this.

Questions specific to Internet Explorer

The toolbar buttons sometimes stop working

This issue was fixed in version 2.0.7.

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 one particular 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.

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 uninstall and then reinstall 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. Consider installing some sort of registry monitoring utility to alert you when something is changed.

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 patent lawsuit.

The change was removed from IE in 2008, so if you apply the latest Windows updates, it should no longer occur.

A similar feature exists in some versions of Opera.

Full-page mode doesn't work in IE6

The symptom here is that Test 3 on our test page does not work, but Tests 1 and 2 do. There are apparently at least three different times that Microsoft has modified IE6 to cause this problem.

1. If you're running Windows Server 2003 Service Pack 2, read Microsoft's article about this.

2. In late 2007, we began receiving sporadic reports of this problem. We've been unable to reproduce it, but some users report that it is caused by Microsoft's security update KB933729 (MS07-058). It's unclear whether it's been fixed by a later update. The only potential workarounds that we know of are to remove the security update listed above (at your own risk), or to use a browser other than IE6.

3. Update KB960714 (MS08-078; December 2008) sometimes causes this problem. It probably only occurs on Windows XP SP2 (not SP3) systems. Reportedly, something in the KB958215 (MS08-073) cumulative IE security update fixes it.

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

We've received a few reports of "Invalid character" or "Object expected" errors occurring even when the "Allow active content..." setting is disabled. We don't know how to reproduce this problem. It's possible that it can be corrected by using the "Internet Options" -> Advanced -> "Reset" feature.

Installing updates from Microsoft disables AlternaTIFF.

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

Our theory is that this only affects people who have installed Microsoft Office 2003 SP3, and is related to the issues described in this article. Unfortunately, that page does not offer a solution.

Presumably, after this happens, you can reactivate or reinstall AlternaTIFF to make it work again. (Or use some other method to restore the "CLSID" registry setting at [HKCR\MIME\Database\Content Type\image/tiff].)

Questions specific to browsers other than Internet Explorer

Web browser won't load AlternaTIFF; uses another plug-in instead.

In sufficiently new versions of Firefox (v5+?), disabling a plugin works sensibly, and file types will not be assigned to disabled plugins. If another plugin is handling TIFF files, and you don't need that plugin, disable it in Tools -> Add-ons -> Plugins.

If this does not apply to you, refer to the detailed information below.

Web browser won't load AlternaTIFF; indicates a missing plug-in (or uses the wrong plugin).

There are too many different and ever-changing web browsers in use for us to try to give step-by-step troubleshooting instructions. What follows is some general information about how browsers handle Netscape-style plug-ins.

Note: Plug-ins are contained in DLL files, which is one of the file types that Windows normally hides from you. To view or 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.

Each browser has its own subfolder named "Plugins", into which plug-in DLL files can be placed. For example, Firefox's is typically located at C:\Program Files\Mozilla Firefox\plugins. Many browsers also search for plug-ins in some other browsers' "Plugins" folders.

Plug-ins can also be registered in the Windows registry under HKLM\Software\MozillaPlugins or HKCU\Software\MozillaPlugins -- this is how newer versions of AlternaTIFF are usually installed. And some browsers have a few other hard-coded places in which they look for plug-ins that they know about (e.g. Windows Media Player).

Browsers scan for plug-in files each time they start, and enable any plug-ins they find. No special configuration is necessary to install a new plug-in. If the plug-in file (AlternaTIFF's is "npzzatif.dll") is found in the Plugins folder or elsewhere, it is considered to be installed. Therefore, to remove a plug-in, it is sufficient to delete or move the DLL file.

To get a list of installed plug-ins, try entering "about:plugins" into your browser's location bar. This should tell you the plug-in file's name (e.g. "npzzatif.dll" for AlternaTIFF), but it may not tell the location of that file, which can be important information when you're trying to resolve plug-in conflicts. If that's a problem, and you're using a Firefox-like browser, you may be able to change this policy by entering "about:config" into the location bar, finding the item named "plugin.expose_full_path", and changing its value from "false" to "true". You should change it back to "false" when you're done.

What happens when more than one plug-in is found that handles a certain type of file? Unless the browser has been configured to do otherwise, it will arbitrarily select one of them, perhaps based on the order in which it encountered the plug-in files while scanning for them.

Some browsers allow you to configure which plug-in you want to use to handle a certain type of file, while others do not, or have only very limited features. Look in the Options/Preferences (and/or Tools -> Add-ons) settings for a section named "Plug-ins" or "Applications" or "File Types" or "Downloads" or "Programs" or something like that. Look for a file type named "image/tiff" or "TIFF", or something like that (it could even be named after your system default TIFF application; e.g. "Microsoft Office Document Imaging File"). Try to configure that file type to be handled by AlternaTIFF (which should be offered in a list of plug-ins).

In rare cases, the plug-in itself has a way to configure the file types it handles. The only such plug-in that we know of is QuickTime, but its configuration utility does not work correctly on versions of Windows newer than XP.

Google Chrome fails to use AlternaTIFF
As of September 2015, Chrome no longer supports plug-ins. We are not aware of any workarounds.

Questions from developers and administrators

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)

Why can't I put other web page elements in front of AlternaTIFF?

AlternaTIFF is a "windowed" control, and as such, it usually cannot be obscured by other elements. Unfortunately, this is unlikely to change, due to the amount of re-engineering it would require to make it windowless.

There is no good, simple solution to this problem. For possible workarounds, search the web for terms like "activex z-index" or "plugin z-index".

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. IE9 seems to not support TIFF content whose URL extension is registered as a type other than TIFF. 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:
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 may 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?

Sorry, but this seemingly simple problem does not have a simple, reliable solution. We suggest searching the internet for "plugin detection". AlternaTIFF's identifiers and file types are listed here.

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.