Phil wrote:There is a function in newer MS Office versions (2003?) that indeed delete all the image parts that were cropped. This may be what simiae is referring to.
I guess it's been quite a while since I've tried cropping any images in Word. However, trying it in Word 2003, I see that the "compress picture" dialog contains an option "Delete cropped areas of pictures".
For my test in Word, I created three new documents and inserted the same 104KB jpg image into each. The first was my control file, saved without performing any action on the image, and its file size was 136KB. In the second, I cropped the image and applied compression
without the delete-crop option, and with no change to the image resolution (so, no compression of the image data and no deleting of cropped bits). Its file size was also 136KB, so no deletion has occurred by cropping alone. The entire image is still there. In the third test I cropped then applied compression
with the delete-crop option, again with no change to resolution, and the result was 48KB.
I then applied compression in the control file to reduce the image resolution for print (as opposed to the other options, Web/Screen or No Change). The file size remained 136KB, which means no data loss occurred with compression---the image was not reduced.
This could mean one of two things, either the file still contains the entire image data (which I doubt because otherwise the compression option would be pointless) or because the jpg is already a compressed format no compression occurred, as it was already at or below the 200 dpi resolution hard-coded for the Print option.
The Web/Screen option is hard-coded for 96 dpi (which makes no sense because displays are in pixels, not dpi). Choosing it reduced the file size to 88KB but the image quality is, of course, visibly affected.
Now, testing the CropOOo extension in Writer 2.4, I inserted that same 104KB image in two new documents. The first is, again, a control document with no change to the image. In the second, I cropped using the CropOOo extension, and in the third, I cropped using the native crop tool. Opening each file with 7-zip and examining the image size, they were all 103KB. (The 1KB difference from the original could be either a difference in rounding the actual file size, or a result of the image being compressed slightly in the .odt archive format. I'm not sure which and, at the moment, don't have the desire to go figure it out.)
So the CropOOo tool doesn't remove image data either, it just makes "cropping" more visual and direct.
I will stand by the recommendation, then, to use an external tool for cropping and reducing file size, and I would recommend it for Word as well. Word's built-in tools are not worth bothering with.