Adobe AIR Development

[JeffLemon]

What's the DPI of the playbook screen?

Thanks

[JRab]

hey jeff,

there have been a few threads about this. but nothing has been confirmed nor denied officially. there have been claims of it having a DPI between the ranges of 168 and 172. unfortunately we cant confirm with the simulator either. so we will either have to wait for the real device or have RIM confirm it for us.

[JeffLemon]

Oh right, so what resolution would you suggest I make my designs in photoshop?

[JRab]

i havent seen anything specific so i've been working with 72 PPI. also the icon "best practices" page states to make icons at 72 PPI. i dont really know how that translates into larger images but for now im sticking with 72. if its too low i can always change it later on down the road.

Edit: Forgot to include a link to the icon resoultion data:

http://docs.blackberry.com/en/developers/deliverables/22301/Designing_application_icons_tablet_14015...

[peter9477]

The pixels are in fact (and officially) sized at 0.15mm which means a DPI of 169.333.  Searching should have turned up several past threads covering this.

Whether the Capabilities.screenDPI value will hold that or something less precise remains to be seen. 

There are signs the device may report itself as being 170 DPI instead of the closer 169, but we won't know until we see the hardware and a final OS build.

[longway77]

The screen measures 153.6mm, which is 6.0472 inch in width. If I use 1024pixels and divide this by those sizes it's about 169 to 170 dpi.

[jffurlan · Accepted solution]

The UI guidelines state that the ppi is 169.3.

http://docs.blackberry.com/en/developers/deliverables/22301/BlackBerry_PlayBook_tablet_characteristi...

[JRab]

ah well played jffurlan

[peter9477]

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JeffLemon wrote:

Oh right, so what resolution would you suggest I make my designs in photoshop?

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Jeff, DPI has nothing to do with resolution unless you specify a particular physical size.  The reason Photoshop lets you give DPI is because it can adjust the resolution as required whenever you print or export for a particular device or physical size.

If you're using Photoshop to generate images for the PlayBook, what matters is what dimensions (resolution) they need to be.  If you have no choice but to specify DPI (unlikely), then figure out what actual size (in pixels) you want the images to be, and adjust DPI until they come out that size when you export.

Better yet, ignore DPI and just make sure you force the dimensions to be what you want.  For icons, that's 86x86, with the primary portion in a 77x77 area within that.  For other stuff... that depends on what size you want things to be in your UI, not on any DPI number.

For raster/bitmap images DPI is a property of a physical display on which it will be shown, not of the image itself.  For vector graphics, DPI is a value specified along with physical dimensions in order for a program to calculate the actual pixel resolution required for an exported bitmap.

[jffurlan]

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JRab wrote:

ah well played jffurian

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Hey, it's about time I gave someone an answer around here instead of just constantly begging for help! lol.

Funny part was I knew I had read it somewhere but couldn't remember if it was on a tech blog or an official statement from BlackBerry. The UI guidelines are a good read though, they actually gave me a lot of good ideas when it comes to laying out your app.