App crashes with very low memory usage iphone/iPad
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I have read lot of posts regarding Low memory warning crash, But I was unable to solve the problem of crash in my app. The Allocation of instruments shows Live bytes ranging from 2-7MB. It never spikes beyond 7 or 7.5MB but still app crashes. 

I read some links which tells that Allocations and Activity monitor shows different values of memory usage. As specified earlier, Allocations will show max of 7-7.5MB but Activity monitor shows about 75MB usage when app is launched and as I use the program, it starts increasing and decreasing. It will go up to 110-120MB and then reduce to 75-80MB.

Some more links says to look at Dirty size and resident size in VM Tracker. When I check in VM Tracker, the Dirty size will start from 30MB and starts to increase as I use the app. It goes beyond 400MB. I am using about 150 images in which about 70-80 are of 1024x1024 size, about 35 are in 110x110 and rest are of 3000x4000 sized image. All of these images were originally in png format and I have programatically converted to JPG+ALPHA and added as asset to a application. Whenever corresponding image has to be loaded, I divide the JPG+ALPHA image into 16 parts and finally join them to get original image. I am doing this because when I tried to load image of resolution 3000x4000, memory was spiking till 40-45MB in Allocations, so used this method. This method makes sure that the memory will never be exceeded more than 10MB.
 
All of these records and statistics are measured using Simulator. 

Application never crashes on Simulator but it crashes on real device. I am using iPad2 for testing. 

Please help me to solve this problem. I am stuck from past 2 days and completely frustrated by seeing app crash.  

