[GR32] How to get image resolution

[WojTec]

Hello guys,

I have small problem with something that probably is very simple. So, I have image in TBitmap32 object and must save it. When I saving it as JPEG I also updating or adding EXIF metadata. One of EXIF field is picture resolution (and second in thumbnail section). How to compute this resolution (the best in inches)?

[rollstuhlfahrer]

To get the resolution in inches you need to know how to compute your inches. Some Images have 120 px/inch and some have 96 px/inch. I think, you can get this factor by reading it from its original file. If you create a Bitmap im your TBitmap32 (like Painting) you can choose a factor. Usually it'S 96 or 120.

Hope I could help.

Bernhard

EDIT: I've tested thin with MSPAINT and the result-image has a resolution of 96 px/inch (=dpi) (see attached screenshot)

[Klaus01]

N'Abend,

is does not make any sense do put the resolution px/inch into the exif.
The resolution is depending on the device where the image will be displayed or printed.

The screen resolution is between 72 and 96px/inch.
A printer can have a resolution of 150,300 or 600 dots(px)/inch.

So an image with an width of 1000 pixels has width on the screen of round about 10 inches.
Printed it is physicaly much smaller.

Hope it helps.

Klaus

[WojTec]

Thanks for answers. I decided to don't save DPI or remove if exists. Thanks guys :)