Memory Required for a Scanned Image

When you scan a photo into a program such as PhotoShop, the image file can be several megabytes (MB) in size. The file size increases with bit depth, resolution, width and height. For instance, a photo scanned at 24 bit (millions of colours), 300 dpi, 288 points wide by 144 points high on screen (about 4 x 2 inches or 10 x 5 cm) requires 2.16 MB of disk space. If the image is twice as wide and high, the area and memory quadruples (8.64 MB in the example).

Memory Required by AppleWorks

PhotoShop and other image software can cater for such large image memory requirements. They often employ their own virtual memory schemes to only load part of the image into RAM, allowing them to deal with images larger than their their allocated RAM. AppleWorks, however, loads each document and it’s contents into RAM when opened. So if AppleWorks has 3MB of free RAM and you attempt to place two 2 MB image files into a document, it will either complain that it has run out of memory or else crash.

If you reduce the image file size, by saving from PhotoShop as JPEG, then the disk space can reduce to as little as 10%. For instance, a 2MB image can be saved as a 200k file. However, if you then bring it into AppleWorks by any one of:

1. Open the image in AppleWorks as a painting document (eg by dragging the JPEG document onto the AppleWorks application).
   
2. Insert or paste the image into an AppleWorks painting document or frame.
   
3. In AppleWorks 5, drag and drop the image file into a drawing or word processing document.
   
   

Then AppleWorks converts the file from JPEG, restoring the original large memory requirements. So, in these cases, the file size savings of a JPEG file are lost.

Solution for AppleWorks 6

With the introduction of AppleWorks 6, Apple added direct support for inserting a compressed image file as a graphic object, without decompression. AppleWorks 6 directly supports JPEG and other compressed formats through QuickTime. So inserting a JPEG file should only require about the same RAM as the space it takes on disk. You can place a JPEG (or other format supported by QuickTime) as a graphic object using one of these methods:

1. Drag the image file from the Finder into an AppleWorks document window, or;
   
2. Use the File:Insert menu item to insert the image file into the open AppleWorks document.
   
   

Solution for Any AppleWorks Version

Although AppleWorks 5 and earlier converts JPEG and other image file formats when importing, it imports PICT files without alteration. Fortunately, the PICT file format supports JPEG compression. It is important to understand that a PICT file with JPEG compression is different to a JPEG file. Although the quality and file size is essentially the same, AppleWorks can import the PICT file using only the reduced memory requirement (eg 200k instead of 2MB).

When saving the image in PhotoShop or other scanning software, save it as PICT. During the save process, the Mac should prompt you to select a compression mechanism, with a dialog box like this:

or an Options button in the Save As dialog that leads to a compression dialog like this:

Select a compression option, such as that above. Then save the document.

If your image software does not provide JPEG compression options when saving a PICT file, then you can:

1. Save as a normal large file size PICT, PhotoShop or other QuickTime supported format.
   
2. Open the large PICT file using PictureViewer (in your QuickTime folder).
   
3. Export as PICT. In the Save As dialog, use the “Options” to compress the file, as in the above figure.
   
   

You can then insert the image file into an AppleWorks document by drag and dropping the image file icon into the document window, or using the File:Insert menu item. AppleWorks will only require the compressed image size amount of RAM to add the image to your document. This works in all document types (eg drawing, word processing) except paint.

Painting Documents and Frames

Do not place the image file into a painting document or frame. Doing so, with any version of AppleWorks, will convert it to AppleWorks native uncompressed painting format. This will restore the large RAM requirements and probably change the screen size or resolution of the image.

It is only worthwhile placing an image file in a painting document or frame if you wish to make edits to the image and you have enough allocated RAM to do so. After editing, you may wish to again compress the image by saving it as a JPEG file, or save as a PICT and compress using PictureViewer.

Instead of editing the content of the image itself, you can often simply place other graphic objects in front of it in the drawing layer.

Limitations

This solution works because QuickTime takes care of the JPEG compression and on screen rendering. Because of this:

1. You must have QuickTime installed. Most versions of the Mac OS include QuickTime and it is a free download.
   
2. Image updating, such as when unhiding a window, or after moving or resizing the image, is slower because QuickTime must decompress the image on-the-fly. This is most noticeable on slower Macs.
   
3. JPEG compression is “lossy”, which means that some detail may be lost. However, JPEG compression is optimized for photos and does a very good job, so you probably won’t notice any loss. You can vary the compression quality to get the right balance of file size vs image quality.
   
4. A compressed image in an AppleWorks document cannot be edited. If you want to touch up the image, either draw over it (ie as separate graphic objects in front of the image), or edit it in the scanning program before saving. If you ungroup the image in AppleWorks, it will convert to a paint frame, with either reduced resolution or increased RAM requirements.
   

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