Sending Pictures With Mail...Sending the Right Size Picture

Question

I'm emailing pictures to an editor from iPhoto. They look fine when I send them. I send them using the actual size tab on mail. However when they get to her, she says they are only 1.5 inches by 1.5 inches even though they are 4X6 pictures when I send them. I don't get it. Anybody have any tips on what's up with this?

Answer 1

Philip,
The compression could have been applied by iPhoto, but the very high resolution value (680) was probably set by your source.
Compression is the whole reason to use JPEG, and its greatest fault. To compress, the photo application uses an algorithm to analyze the photo by detail. If a photo had a large wall pictured that was all the same color, then the algorithm performs coding to say that this large area is all the same color and does not use separate pixels for each portion of the area. How small a file can result from the compression is dependent upon the variation of color and detail in the photo. The next photo app to open applies the reverse algorithm to decompress. This is also done in cameras that save their photos in JPEG on the memory card.
JPEG can be used once with fairly good results, but if a photo is changed and then compressed again to save as JPEG then it can lose quality and sharpness.
Resolution is strictly the number of pixels per square inch and how much detail can be recognized and preserved in the photo (uncompressed). When you send a JPEG version of a quality TIFF or PSD format folder (or from a RAW photo taken with a good camera), and specify actual size, what that means is that the resulting file will be as large when decompressed and contain just as many pixels as the original, but depending upon the amount of compression selected can be a much smaller file to attach and email.
I am still researching how you might select to send such photos in the future, but what you were sent may be the controlling factor.
Before getting Aperture, I primarily used ordinary folders to store my photos, and opened them with Photoshop or Graphic Converter (the latter having an excellent interface with Mail. My use of iPhoto was limited (and still is) to those situations where its very good interface with other Apple applications is needed. Thus I do not know nearly as much about iPhoto as I do about Photoshop, Aperture, and other photo applications. But I do know that iPhoto will maintain the original quality, but the issue you presented is related to presenting for an email and for exporting.
More when I find it.
Ernie