Ask Your Question

Revision history [back]

click to hide/show revision 1
initial version

Cascade training - negative images

Using the create samples application I can create an arbitrary amount of positive images from a small set (whilst not always the best option, it does save time). My first question is ideally what should the ratio be between positive and negative images (including the samples generated) - and does that affect the run time of opencv_train cascade. Im currently running a trainer with POS count = 1000, NEG count acceptanceRatio 48:1.

My other questions are about the quality and size of negative images. Is there any advantage to having high resolution (several MB) negatives if the ultimate application of the detector is a Kinect camera? Also, does it matter what the negative images are? I just used random holiday photos for my first test and the quality of my detector wasnt brilliant.

Cascade training - negative images

Using the create samples application I can create an arbitrary amount of positive images from a small set (whilst not always the best option, it does save time). My first question is ideally what should the ratio be between positive and negative images (including the samples generated) - and does that affect the run time of opencv_train cascade. Im currently running a trainer with POS count = 1000, NEG count acceptanceRatio 48:1.48:1. It has been on training stage 0 for a while now.

My other questions are about the quality and size of negative images. Is there any advantage to having high resolution (several MB) negatives if the ultimate application of the detector is a Kinect camera? Also, does it matter what the negative images are? I just used random holiday photos for my first test and the quality of my detector wasnt brilliant.

Cascade training - negative images

Using the create samples application I can create an arbitrary amount of positive images from a small set (whilst not always the best option, it does save time). My first question is ideally what should the ratio be between positive and negative images (including the samples generated) - and does that affect the run time of opencv_train cascade. Im currently running a trainer with POS count = 1000, NEG count acceptanceRatio 48:1. It has been on training stage 0 for a while now.750:1.

My other questions are about the quality and size of negative images. Is there any advantage to having high resolution (several MB) negatives if the ultimate application of the detector is a Kinect camera? Also, does it matter what the negative images are? I just used random holiday photos for my first test and the quality of my detector wasnt brilliant.

Cascade training - negative images

Using the create samples application I can create an arbitrary amount of positive images from a small set (whilst not always the best option, it does save time). My first question is ideally what should the ratio be between positive and negative images (including the samples generated) - and does that affect the run time of opencv_train cascade. Im currently running a trainer with POS count = 1000, NEG count acceptanceRatio 750:1.

My other questions are about the quality and size of negative images. Is there any advantage to having high resolution (several MB) negatives if the ultimate application of the detector is a Kinect camera? Also, does it matter what the negative images are? I just used random holiday photos for my first test and the quality of my detector wasnt brilliant.

EDIT: The application is ultimately to detect various sizes of coffee cups in a crowded environment with varying lighting to do some 2d-3d mapping etc. As I understand, as the cups will all have rigid distinct geometric features with little variance, I don't entirely need to create a lot of distorted images with create_samples. I think it would be better to have a very wide negative library to cover for the varied lighting.

Another question - how well should the positives be cropped?