Protect Web Images - how to configure and use Image Guardian
Only
protect web images
bigger than X
x X pixels
In many websites there are a lot of small images for which there is
no need of whatever image protection. Here you can specify the minimum
image size that does not need a protection.
If you specify here let's 50 x 50
pixels as a minimum image size, any image with a width < 50 pixels
and a height < 50 pixels will
not be protected. All images outside this range will be protected, like
100 x 30 pixels images.
There are two ways to define how to split the protected web images
- you can choose to split them always into fixed number of pieces regardless
of their size (check Always divide images into X x X pieces)
or you can choose to fix the size of the pieces, in which case bigger
images will be splitted into more pieces (check Divide images into
pieces with a side of X pixels).
Note that if you use the second option, the value specified for the
side of the pieces will not be strictly observed, it will only be
used by Image Guardian as a basis to calculate the actual number of
pieces to split the image into. If for example you enter 100 pixels
there,
250 x 200 pixels image will be divided
into 4 pieces 125
x 100 pixels.
Any image bigger than the specified minimum size will be divided into
at least 2 pieces. If you specify 50 x 50
as a minimum size and 100 pixels image
pieces size, 80 x 40 image will be divided
into 2 pieces 40
x 40 pixels each.
The smallest acceptable minimum image size is 40 x 40 pixels, so any file below this size will remain unprotected (only if both sides are below 40 pixels, this restriction does not apply for files like 100x20).
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Quality - the quality of the protected
image pieces. We suggest to leave the default value of 85 - this will
preserve the original image quality without increasing the image size.
Setting this value to 85 does not mean that the original image
quality will be decreased by 15% - it will be preserved.
Any value outside the acceptable range of 60 - 100 will be ignored by the program and
the default value of 85 will be used instead.
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Run Image Guardian in Safe Mode - check this
box if you experience problems with protected files (images are not
protected, protected images are not displayed in the encrypted files
etc.). HTML Guardian will encrypt the files slower if Image Guardian
runs in Safe Mode.
When HTML Guardian is running, you can press Ctrl + Alt + S keys
to toggle Image protection Safe Mode OFF/ON. Press F4 at any time
to see the current settings.
Safe Mode level ( 1 - 10 ) - in case the 'Run Image Guardian in
Safe Mode' box is checked, here you can specify the Image Guardian
Safe Mode level. Higher Safe Mode levels will result in a slower encryption
process. The default Safe Mode level is 3.
You should increse the Safe Mode level in case you experience problems
with the current Safe Mode level. In general, the slower your PC is,
the higher Safe Mode level should be specified. Use Safe Mode level
> = 6 for really slow machines (CPU speed < = 350 MHz, RAM <
= 64 MB).
For faster machines(above 800 - 1000 MHz CPU speed), you may uncheck
the Run Image Guardian in Safe Mode box (in this case the Safe
Mode level setting value doesn't matter).
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Note: After you make whatever changes in Image Guardian
configuration, you have to click 'Save settings' button to save
them. Most of the configuration changes will have no effect before restarting
HTML Guardian.
You can toggle Image Guardian OFF/ON and Image Guardian Safe Mode OFF/ON
while HTML Guardian runs, but this will change those options only for
the current session.
All the changes made in Image Guardian configuration will become effective
after HTML Guardian is restarted.
Defining which images to be protected:
By default Image Guardian will protect all web images in the html file
bigger than the specified minimum image size, but there are several
ways to define exactly which images to protect in case you don't want
to protect all of them. Of course, image protection must be enabled
for those settings to become effective.
If you want to protect only let's say 2 images, cat.jpg
and dog.gif, and leave the rest
unprotected, include this html comment tag anywhere in the body of the
html file:
<!--ig_include:cat.jpg;dog.gif -->
If you want to protect all images in the html file except cat.jpg
and dog.gif, use the following comment
tag:
<!--ig_exclude:cat.jpg;dog.gif -->
To disable Image Guardian for a specific file only, insert this tag
in it:
<!--ig_disabled --> - no image
will be protected in this page even if Image Guardian is currently enabled.
These comment tags are CaSe SeNsItIvE and should be in lower case (except
the image file names - they are not case sensitive).
Do not include path information, it's enough to include the file name
only. Even if the relative path to a file is lets say Images\cat.jpg,
it's enough to put in the comment tags cat.jpg
only.
Of course you don't have to exclude files smaller than the specified
minimum image size - they will be skipped automatically.
Image Guardian specifications
and limitations - what it can and what it can't do
Accepted input file formats: *.jpg, *.gif, *.bmp - any image
in another format (like *.png) will not be protected.
Output file format: always *.jpg No matter if the image to be
protected is in jpg, gif or bmp format, if image protection is used
it will be always divided into pieces saved in jpg format. The reason
is gif format is patented and some legal issues may arise, and the
bmp format is not widely supported by the browsers and is almost never
used in websites. So Image Guardian provides a convenient way to use
bmp files directly without having to convert them - it will do that
for you.
Image Guardian can only protect web images in html / shtml / php files.
We plan to add Image Guardian support for .asp files soon.
Image Guardian can not be used when you use Ultra
- Strong password protection.
At this time Image Guardian can only protect web images inserted
in the html document with the <IMG...> tag and with a relative
path (image should be available locally).
Images included this way
<IMG src = "myimg.jpg">
<IMG src = "images/myimg.gif">
will be protected.
Images included this way
<IMG src = "http://www.mydomain.com/myimg.jpg">
will not be protected - Image Guardian will not download them
from the web location, and it does not know where to look for them on
the local hard drive
Background images and image maps will not be protected.
Animated *.gif files can be protected, but the animation will be lost.
You can use the comment tags described above to tell Image Guardian
not to protect them.
Any javascript functions triggered by image related events (onClick,
onMouseOver etc) may not work. For example
<IMG src = "myimg.jpg" onClick
= alert("Hi there")>
After the image is protected, no alert will be displayed when you click
it.
Image alt attribute,if any, will
be lost (alt is used to display a tooltip when the mouse is over the
image, or to display some text in the place of the image if for some
reason the image was not loaded).
<IMG src = "cat.jpg" alt
= "My cat">
In most cases, protected images can't be manipulated through scripts.
You can't have a rollover effect that uses protected images, to have
a script that rotates several protected images, etc
Image Guardian may not protect images in html files which contain
a code that automatically redirects the browser
to another file. This is a very rare situation though.
Any event driven redirections(like when a link is clicked) are not a
problem.
Image Guardian and HTML
Guardian Profiles & File lists
Image Guardian settings are not stored in HTML Guardian Profiles
and File Lists. When you encrypt a file list, the current web image
protection settings will be applied. This is the same for HTML Guardian
profiles, any profile you load will use the currently specified Image
Guardian settings.
At this time it is not possible to use a different predefined set of
Image Guardian settings for each HTML Guardian profile or file list
- always the current Image Guardian settings will be applied.
There are certain things to consider when you encrypt file lists. Let's
see an example:
You have added the following file to a filelist: C:\Test\index.htm
You have specified the encrypted version of this file to be saved as
C:\Test\Encrypted\index.htm
In the Image Guardian settings window, you have specified the protected
images to be stored in \e_imgs subfolder.
Lets say C:\Test\index.htm contains two
web images which are in the same folder, e.g.C:\Test
After you encrypt the filelist, the pieces of the protected images will
be stored in C:\Test\e_imgs folder. But
the encrypted file that uses them will be in C:\Test\Encrypted
folder - this means the relative paths from the encrypted file to the
protected images will be incorrect, and the images will not be displayed.
You should cut the C:\Test\e_imgs folder
and paste it inside C:\Test\Encrypted folder.
The same problem may appear if you encrypt a single file ( with web
images protection enabled ) and decide to save the encrypted file in
another folder(not where the original file is).
When you encrypt a folder or a site, HTML Guardian will first create
a copy of this folder(site) and will encrypt the files inside that copied
folder. All relative paths within that new folder will be correct and
you don't have to do anything.
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