How much memory will java.awt.Image consume if JPEG is 10MB?

问题

MTOM is usually used to transfer image data over SOAP (attachments). The image is mapped to a java.awt.Image (at least with CXF). Does the Image object consume a lot more memory than the actual image transferred? Let's say a transferred JPEG is 10MB, how much more space will the Image object consume?

UPDATE - I'm not so sure it has anything to do with java.awt.Image at all. Focusing on CXF/MTOM more at the moment: http://cxf.547215.n5.nabble.com/MTOM-large-attachments-eating-up-JVM-heap-td5714196.html

回答1:

Does the Image object consume a lot more memory than the actual image transferred?

Typically yes. The idea of most of the file formats is to compress image data.

Let's say a transferred JPEG is 10MB, how much more space will the Image object consume?

The RAM size depends on W * H * 'pixel depth'. E.G. RGBA in 256 shades is 4 bytes per pixel. JPEG does not support alpha transparency, so it would be 3 bytes per pixel.

For some idea of the effectiveness of JPEG compression efficiency at different levels, see this answer: