C# Win. Form - Out of memory when retrieving an Image

Question

Brief

I want to display a PNG image in my PictureBox. At runtime the software asks the path of the image from the user.

Solution i am using

This is my code uptill now

picturebox1.Image = null;
OpenFileDialog ofDlg = new OpenFileDialog();
ofDlg.Filter = "Image files|*.png";
if (DialogResult.OK == ofDlg.ShowDialog())
{
     picturebox1.Image = Image.FromFile(ofDlg.FileName); //Out of memory.
}

Problem

It was all working fine uptill now untill i got an image which was of 25.7 MB (8827 x 11350 pixels).

I know you might all suggest that i should get a lighter version of this image BUT the problem is that this software is used to zoom the image to view the image in detail. So i cannot resize it at any cost.

Now whenever i run the above code it gives me the exception

Out of memory.

I do not understand what is the problem here because i have 8GB of RAM installed on my PC then how it is out of memory? Below is my CPU usage at the time when this error message appeared.

Possible duplicate https://stackoverflow.com/questions/1108607/out-of-memory-exception-on-system-drawing-image-fromfile — schlonzo, Jul 04 '18 at 08:08
@Smartis i cant because even after applying a try catch the error pops up on the `picturebox1.Image = Image.FromFile(ofDlg.FileName);` line — Agent_Spock, Jul 04 '18 at 08:08
@LasseVågsætherKarlsen that may be the case but i have 4 GB of free space at that partciular point of time. — Agent_Spock, Jul 04 '18 at 08:11
Sadly the bitmap is not 24 but 32 bit to start with - alpha channel and staying to a "sane" byte layout for the graphics card mandates 32 bit bitmaps. And you need this memory without interruption which is HARD for a 32 bit program to get. — TomTom, Jul 04 '18 at 08:11
Perhaps, but perhaps not 286 *continuous* available space, or 382 if 32-bit. — Lasse V. Karlsen, Jul 04 '18 at 08:11
@LasseVågsætherKarlsen so what shall i do ? i cant re-arrange RAM memory allocation (out of my skill level) — Agent_Spock, Jul 04 '18 at 08:12
You should use a tool to convert the image into a format suitable for random access to the pixels, and rewrite your program accordingly. — Lasse V. Karlsen, Jul 04 '18 at 08:13
Or implement the loading yourself so that you don't need continuous memory. — Lasse V. Karlsen, Jul 04 '18 at 08:14
@LasseVågsætherKarlsen do you know how to read a part of the image? i will try to read it part by part and apply some algo on it — Agent_Spock, Jul 04 '18 at 08:15
No, I don't, you're likely going to have to find a 3rd party library to help you — Lasse V. Karlsen, Jul 04 '18 at 08:18
From .net 4.5.1: https://blogs.msdn.microsoft.com/mariohewardt/2013/06/26/no-more-memory-fragmentation-on-the-net-large-object-heap/ — PepitoSh, Jul 04 '18 at 08:20
@Agent_Spock - Does this error occur the first time you load this image or does it work for a while before the error? — Enigmativity, Jul 04 '18 at 08:22
@Enigmativity after a while.....btw "The General"'s solution worked but trying to figure out why? — Agent_Spock, Jul 04 '18 at 08:24
@Agent_Spock - I would think you are running out of O/S graphic handles. When they run out they report as an out of memory error even though you have heaps of memory free. There are just a limited number of handles and disposing releases them. — Enigmativity, Jul 04 '18 at 09:07

score 2 · Accepted Answer · answered Jul 04 '18 at 08:19

2

Follow the sugestions of all the comments, i.e Make sure you are in 64 bit

But you need to also make sure you are disposing your images or you will run out of memory sooner or later anyway. The following is just an exmaple

if(picturebox1.Image != null)
   picturebox1.Image.Dispose();

picturebox1.Image = null;

OpenFileDialog ofDlg = new OpenFileDialog();
ofDlg.Filter = "Image files|*.png";
if (DialogResult.OK == ofDlg.ShowDialog())
{
     picturebox1.Image = Image.FromFile(ofDlg.FileName); //Out of memory.
}

answered Jul 04 '18 at 08:19

TheGeneral

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this actually worked BUT i do not understand why it worked? was it keeping every image in the memory that has been set to picturebox? because i never saw increment of RAM usage after every image view. – Agent_Spock Jul 04 '18 at 08:23
@Agent_Spock Yeah a lot of bad things happen when you dont dispose images, first is a big memory leak, however the second is that you have unmanaged file handles and such hanging around if you read them from disk – TheGeneral Jul 04 '18 at 08:25
sorry i am not a professinal like you but how "unmanaged file handles" still lurk around when i have changed my image? – Agent_Spock Jul 04 '18 at 08:27
1

Because the image keeps a reference to them from the operating system until you dispose them and it cleans it self up. by not disposing you are never allowing the image to clean itself up, things are'nt going out of memory in a variety of different ways – TheGeneral Jul 04 '18 at 08:29
It's not a memory issue, it's a O/S graphics handle issue. – Enigmativity Jul 04 '18 at 09:08
GDI Process Handles to be precise. – Enigmativity Jul 04 '18 at 09:13
1

@Enigmativity yeah gdi handle, file handle, any managed memory, however yeah the out of memory is gdi – TheGeneral Jul 04 '18 at 09:14

C# Win. Form - Out of memory when retrieving an Image

Brief

Solution i am using

Problem

1 Answers1