What dictates picture size on incoming phone calls?

[donawalt]

Hopefully someone can explain this to me...

I got a phone call from my daughter today on my iPhone 5. The picture on her Contact comes from her Google+ account, as Gmail stuffs it in and then I sync to the iPhone. So when she calls, the picture is smallish in the top right corner of the screen, and there is a big picture that is my background lock picture.

So as an experiment, I took a picture of her with the iPhone camera, and made that her contact picture. She called me again, now there is just a big picture of her, and it's the one I just took.

How does this work? Why a small picture with background vs. a full size picture?

 

[Massie]

They are big if taken on the device, and small when synced via google contacts. (I think because Google uses a low res version, so it is kept at a small size.)

 

[trmoney24]

Same thing happens when you sync a contact with Facebook. The picture will be small.

 

[mcscrufff]

I have done many experiments and found that there are a greater number of subtleties in setting small-size or full-screen phonecall alert photos on the iPhone. See my notes below and choose the ones relevant to you.

NOTES:
I wanted **LARGE* phonecall alert contact photos when receiving phonecalls on my iPhone. Some tips on how to achieve this …

.The contact photo size must be greater than or equal to 320x320Px for display in FULL-SCREEN size in the iPhone call alert. To achieve phonecall alert photos, lower resolution contact photos can be re-sized to 320x320px (or greater) by a photo editor (e.g. Microsoft Office photo editor). Alternatively, to achieve small-size alert photos, higher resolution contact photos can be re-sized to less than 320x320px by a photo editor.

.iCloud automatically crops contact photos to square (aspect ratio 1:1). Sometimes this cropping produces undesired results. To ensure desired results, crop the photo to square **BEFORE** uploading to iCloud.

.The large-size iPhone alert images use the contact photo with both **SIDES** significantly cropped to match the iPhone display aspect ratio (4:3 for iPhone 4/4S and 16:9 for iPhone 5). To avoid undesired cropping of a face or other image, allow plenty of space to the left & right of the required image in the contact photo.

.If the contact photo is input in Outlook, the size is reduced to below 320?320 during the upload from Outlook to iCloud resulting in the iPhone phonecall alert photo being small. So, the photo must be entered in iCloud (or on the iPhone). Outlook contacts **TEXT** edits do not affect the iCloud photo size when they are uploaded during a refresh exercise.

.The Outlook 2010 ‘Contact Cards’ display (showing multiple contacts) doesn’t automatically update a contact photo when it is updated from iCloud. The **INDIVIDUAL** Outlook contact must be open when the iCloud contact is updated, then closed, then reopened to see the updated Outlook contact photo. If the Outlook 2010 ‘Contact Cards’ display (showing multiple contacts) is not updated, copy & paste the contact. The newly pasted Outlook 2010 contact should have the photo updated. Then delete the old Outlook 2010 contact.

.If a contact photo is edited in Adobe Photoshop, it seems to display on the iPhone in small format even when the size is greater than or equal to 320x320px. A solution is to open the photo in the Microsoft Office photo editor, resize it by 200%, save it, resize it by 50% (back to original size), then save it again.