<ImageOptions>
<AltText value="exclude"/>
<Images value="include"/>
<ResizeLargeImages value="yes"/>
<MaximumWidth value="144"/>
<MaximumHeight value="144"/>
<ImproveContrast value="yes"/>
<Dither value="yes"/>
<Compress value="yes"/>
<LossyLevel value="none"/>
<LossyQuality value="75"/>
<BitDepth1 value="exclude"/>
<BitDepth2 value="exclude"/>
<BitDepth4 value="exclude"/>
<BitDepth8 value="exclude"/>
<BitDepth16 value="include"/>
</ImageOptions>
| Tag | Type | Default | Description |
|---|---|---|---|
<AltText>
| value | exclude | Whether to include the alternative text of images |
<Images>
| value | include | Whether to include images |
<ResizeLargeImages>
| value | yes | Whether to resize large images |
<MaximumWidth>
| value | 144 | Maximum image width |
<MaximumHeight>
| value | 144 | Maximum image height |
<ImproveContrast>
| value | yes | Whether to improve the image contrast |
<Dither>
| value | yes | Whether to dither images |
<Compress>
| value | yes | Whether to compress images |
<LossyLevel>
| value | none | Types of images to which to apply lossy compression This option requires version 4.0 or later of iSiloX and iSiloXC. |
<LossyQuality>
| value | 75 | Lossy compression image quality. This option requires 4.0 or later of iSiloX and iSiloXC. |
<BitDepth1>
| value | exclude | Whether to include 1-bit versions of images |
<BitDepth2>
| value | exclude | Whether to include 2-bit versions of images |
<BitDepth4>
| value | exclude | Whether to include 4-bit versions of images. Note that before version 4.27 of iSiloX and iSiloXC, the default was include. |
<BitDepth8>
| value | exclude | Whether to include 8-bit versions of images |
<BitDepth16>
| value | include | Whether to include 16-bit versions of images |
include
or exclude to respectively include or exclude
the alternative text of images.
In an HTML file, references to images often also include alternative
text that can be used in place of the image. If you choose not to
include images, you are recommended to include the alternative
text of images so that images that serve as hyperlinks can still
be utilized.
Examples
This example specifies that the alternative text of images
should be included.
<AltText value="include"/>This example specifies that the alternative text of images should not be included.
<AltText value="exclude"/>
include
or exclude to respectively include or exclude
images.
This setting applies to root source file images, images referenced
through HTML <img> tags, and images that are hyperlink targets.
If you include images, you can also set various options for them.
Examples
This example specifies that images should be included.
<Images value="include"/>This example specifies that images should not be included.
<Images value="exclude"/>
yes
or no to respectively enable or disable
resizing of images larger than the specified maximum width
or height as given by the MaximumWidth and MaximumHeight
elements.<ResizeLargeImages value="yes"/>This example specifies that images should not be resized.
<ResizeLargeImages value="no"/>
<MaximumWidth value="144"/>This example specifies a maximum width of 304 pixels for images.
<MaximumWidth value="304"/>
<MaximumHeight value="144"/>This example specifies a maximum height of 304 pixels for images.
<MaximumHeight value="304"/>
yes
to improve the contrast for black and white and grayscale images.
Set the value attribute of the tag to no
to leave the contrast as it is.<ImproveContrast value="yes"/>This example specifies that the contrast of images should not be changed.
<ImproveContrast value="no"/>
yes
or no to respectively enable or disable
dithering of images.
Dithering improves the look of an image when converting
it to a lower color bit depth by diffusing the error introduced
in lowering the number of colors available for use.
Dithering has no effect when the image only consists of colors
from the target color bit depth.
Examples
This example specifies that images should be dithered.
<Dither value="yes"/>This example specifies that images should not be dithered.
<Dither value="no"/>
yes
or no to respectively enable or disable
compression of images. Compressing images generally reduces
the space required to store the images, resulting in smaller
document sizes.<Compress value="yes"/>This example specifies that images should not be compressed.
<Compress value="no"/>
none: Do not apply lossy compression to any images
lossy: Only apply lossy compression to lossy
source images only (i.e., JPEG source images)
200: Only apply lossy compression to images
with at least 200 unique colors
100: Only apply lossy compression to images
with at least 100 unique colors
50: Only apply lossy compression to images
with at least 50 unique colors
20: Only apply lossy compression to images
with at least 20 unique colors
10: Only apply lossy compression to images
with at least 10 unique colors
all: Apply lossy compression to all images
Note that the value attribute of the Compress element must also
be set to yes to enable lossy compression.
Examples
This example specifies that lossy compression should not be
applied to any images.
<LossyLevel value="none"/>This example specifies that lossy compression should be applied to any images with at least 100 unique colors.
<LossyLevel value="100"/>
Note that regardless of the image quality setting,
lossy compression applied to an image always results in a reduction
in the fidelity of the image. So even an image quality setting
of 100 results in a reduction in image fidelity.
Examples
This example sets the quality of lossy compressed images to 90.
<LossyQuality value="90"/>This example sets the quality of lossy compressed images to 48.
<LossyQuality value="48"/>
include
or exclude to respectively include or exclude
versions of images at the corresponding bit depth.
If you are creating a document for use on different devices with different types of displays and different versions of Palm OS®, then you may need to include images at more than one color bit depth. If you are creating a document for use on only one device, then it is usually sufficient for you to include images at only one color bit depth. You can include images at the following bit depths:
The following table lists the Palm OS® versions and the maximum image color bit depths supported.
| Palm OS® version | Maximum depth | Notes |
|---|---|---|
| 3.0/3.1/3.2 | 2-bit | None |
| 3.3 | 4-bit | None |
| 3.5 | 4-bit/8-bit/16-bit | Non-color devices display images at a maximum color depth of 4-bit. The only color device running Palm OS® 3.5 that can display images with 16-bit color is the Visor® Prism. |
| 4.0 | 4-bit/16-bit | Non-color devices display images at a maximum color depth of 4-bit. |
On any supported device, regardless of the color depths supported
and regardless of what bit depths are included for the images,
iSilo™ will still display each image by either choosing the
highest supported bit depth of the image or using the closest available
colors to display each color of the image. No dithering is applied in the
latter case, so the image may not appear as good, but the effect
is usually usable.
Examples
This example specifies that only 4-bit and 16-bit versions of images
should be included.
<BitDepth1 value="exclude"/> <BitDepth2 value="exclude"/> <BitDepth4 value="include"/> <BitDepth8 value="exclude"/> <BitDepth16 value="include"/>This example specifies that only 2-bit versions of images should be included.
<BitDepth1 value="exclude"/> <BitDepth2 value="include"/> <BitDepth4 value="exclude"/> <BitDepth8 value="exclude"/> <BitDepth16 value="exclude"/>