Out of memory error when loading images

Put the summary of the bug you're having here

What I expected to happen was...:
Describe what you thought should happen here

*What actually happened was...:*it got crashed, dont know how?
Describe what happened here

Steps to Reproduce:
1. Put a step by step guide on how to trigger the bug here
2. ...- Minecraft Crash Report ----
// Hey, that tickles! Hehehe!

Time: 20-02-14 12:20
Description: Registering texture

java.lang.OutOfMemoryError: Java heap space
at java.awt.image.DataBufferByte.<init>(Unknown Source)
at java.awt.image.ComponentSampleModel.createDataBuffer(Unknown Source)
at java.awt.image.Raster.createWritableRaster(Unknown Source)
at javax.imageio.ImageTypeSpecifier.createBufferedImage(Unknown Source)
at javax.imageio.ImageReader.getDestination(Unknown Source)
at com.sun.imageio.plugins.png.PNGImageReader.readImage(Unknown Source)
at com.sun.imageio.plugins.png.PNGImageReader.read(Unknown Source)
at javax.imageio.ImageIO.read(Unknown Source)
at javax.imageio.ImageIO.read(Unknown Source)
at bqs.b(SourceFile:112)
at bqs.a(SourceFile:90)
at bqy.a(SourceFile:72)
at bqy.a(SourceFile:61)
at bqy.a(SourceFile:52)
at azi.ad(SourceFile:422)
at azi.f(SourceFile:696)
at net.minecraft.client.main.Main.main(SourceFile:152)

A detailed walkthrough of the error, its code path and all known details is as follows:
---------------------------------------------------------------------------------------

– Head –
Stacktrace:
at java.awt.image.DataBufferByte.<init>(Unknown Source)
at java.awt.image.ComponentSampleModel.createDataBuffer(Unknown Source)
at java.awt.image.Raster.createWritableRaster(Unknown Source)
at javax.imageio.ImageTypeSpecifier.createBufferedImage(Unknown Source)
at javax.imageio.ImageReader.getDestination(Unknown Source)
at com.sun.imageio.plugins.png.PNGImageReader.readImage(Unknown Source)
at com.sun.imageio.plugins.png.PNGImageReader.read(Unknown Source)
at javax.imageio.ImageIO.read(Unknown Source)
at javax.imageio.ImageIO.read(Unknown Source)
at bqs.b(SourceFile:112)
at bqs.a(SourceFile:90)

– Resource location being registered –
Details:
Resource location: minecraft:textures/atlas/blocks.png
Texture object class: bqs
Stacktrace:
at bqy.a(SourceFile:72)
at bqy.a(SourceFile:61)
at bqy.a(SourceFile:52)
at azi.ad(SourceFile:422)

– Initialization –
Details:
Stacktrace:
at azi.f(SourceFile:696)
at net.minecraft.client.main.Main.main(SourceFile:152)

– System Details –
Details:
Minecraft Version: 1.7.4
Operating System: Windows 7 (x86) version 6.1
Java Version: 1.7.0_40, Oracle Corporation
Java VM Version: Java HotSpot(TM) Client VM (mixed mode, sharing), Oracle Corporation
Memory: 18446328 bytes (17 MB) / 518979584 bytes (494 MB) up to 518979584 bytes (494 MB)
JVM Flags: 2 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx512M
AABB Pool Size: 0 (0 bytes; 0 MB) allocated, 0 (0 bytes; 0 MB) used
IntCache: cache: 0, tcache: 0, allocated: 0, tallocated: 0
Launched Version: 1.7.4
LWJGL: 2.9.1
OpenGL: Intel(R) HD Graphics Family GL version 3.0.0 - Build 8.15.10.2253, Intel
GL Caps: Using GL 1.3 multitexturing.
Using framebuffer objects because OpenGL 3.0 is supported and separate blending is supported.
Anisotropic filtering is supported and maximum anisotropy is 16.
Shaders are available because OpenGL 2.1 is supported.

Is Modded: Probably not. Jar signature remains and client brand is untouched.
Type: C
3. ...