problem solved

sorry, i've made a mistake

there are other programme running witch causing the lower speed

On Tue, Jun 9, 2009 at 2:26 PM, Alex Tao <> wrote:
Dear VXL users:

    I try to access the image data using iterator

    vil_image_view<float> img(....);
    float *iterator = img.begin();
    float output =  *(iterator+100);

    this section above will repeat millions of times. 

    the computing speed is slower (30%) than the one using opencv witch is using array


    IplImage *img = cvCreateImage(.....);
    float *data = (float *) img->imageData;
    float output =  data[100];
    they are both using gray image

    Did i miss something ?