大图像上的ImageResizer内存不足异常

Question

I have inherited a site which is plagued with oversized and uncompressed images so I am automating the task of correcting it which is mostly working except for files over a certain size. For instance, I have a JPG image which is 8176x6132 300dpi and 24 bit depth, the file size is 4.49mb.

Here is my ImageJob

var instructions = new Instructions("width=1920;height=0;mode=max");
var resizedImg = new ImageJob(filePath, filePath, instructions).Build();

I have plenty of available resources on my machine yet get out of memory exceptions. As I test this right now I have 90% CPU free and 51% memory.

My machine has:

• Intel® CoreTMi7 Quad Core Processor i7-4790 (3.6GHz) 8MB Cache
• 16GB KINGSTON DUAL-DDR3 1600MHz

Why would this fail? As I run the ImageJob there is no increased usage of memory before it fails (as far as I can see).

I am using ImageResizer 3.4.3 with DiskCache plugin.

I should also note that I can open problem files in Photoshop, resize down to say 3000px along the long side, save and then run the same ImageJob which then completes without error.

Diagnostics page output and exception stack trace

Answer 1

First, run the process in 64-bit mode instead of 32. It will have a better chance at locating the required 150mb, 62mb, and 12mb blocks of contiguous memory that way. It's possible another 200mb might be required if you were triggering a fallback code path, or if the image was a CMYK jpeg (common) or had issues.

Second, since you're not using the URL API, make sure that you've limited the number of concurrent images you want to process. In ImageResizer v3, do them 1 or 2 at a time.

Third, upgrade to v4 and use the FastScaling plugin. You'll get actual concurrency , and large blocks of RAM will be held for smaller amounts of time, meaning your throughput can easily go up 10x on files this large.