SURF features from RGB

In Bag of Features, I can use SURF detection on my datastore of RGB images. When I use the detectSURF alone it requires only grayscale images. I want the features extracted from the Bag of Features function, but I want to maintain the location of points for each individual image and save figures with the valid_points plotted on the image. If Bag of Features can use SURF on RGB images, why can't I apply the same function individually?

Answer 1

[Shashank Gupta]

Hi Olivia,

Bag of features also uses the same “detectSURF” function to detect the surf features. Although you are storing RGB images, but interior in the bag of feature function it changes the RGB images to GRAY and then feed it to “detectSURF” function to extract the features.

You can cross check this by looking at the bagOfFeatures.m file in MATLAB

Try,

edit bagOfFeatures.m

I hope it helps you.

[Olivia Harris]

Okay, thank you! Is there another function that can achieve the same feature extraction in matlab that can also be used to classify images that includes color information?