findContours crashes on very large images

[reunanen]

System information (version)

• OpenCV => 2.4.13 (official binaries)
• Operating System / Platform => Windows, 64-bit
• Compiler => Visual Studio 2013, Update 4

Detailed description

Function findContours crashes my program for very large images (e.g. 79925 * 49955), apparently regardless of the image contents.

Steps to reproduce

Code:

cv::Mat largeImage(79925, 49955, CV_8UC1);
largeImage.setTo(0);

// this is not really even needed to reproduce
cv::circle(largeImage, cv::Point(largeImage.cols, largeImage.rows), 1000, 255, CV_FILLED);

std::vector<std::vector<cv::Point>> contours;
cv::findContours(largeImage, contours, cv::RETR_EXTERNAL, cv::CHAIN_APPROX_SIMPLE);

The last line crashes the program. Works great for smaller images (didn't find the exact limit though).

I don't think I'm running out of memory (have multiple gigabytes left), and even if I was, it'd be better to receive an exception of course.

Can anyone reproduce this?

Haven't tried on version 3 yet.

[reunanen]

Seems to be coming from here:

The calculation step * (size.height - 1) overflows (the type is int).