Hello. I used Openmv M7, When I find AprilTag, I met a Error:" MemoryError: Out of fast Frame Buffer Stack Memory! Please reduce the resolution of the image you are running this algorithm on to bypass this issue!", if the distance is over about 40 centermeter, IDE will jump this error.
I want to increase the Frame rate, so I used ROI to Zoom out the range.
Here is my code:
# AprilTags Example # # This example shows the power of the OpenMV Cam to detect April Tags # on the OpenMV Cam M7. The M4 versions cannot detect April Tags. import sensor, image, time, math sensor.reset() sensor.set_pixformat(sensor.GRAYSCALE) sensor.set_framesize(sensor.QQVGA) # we run out of memory if the resolution is much bigger... sensor.skip_frames(time = 2000) sensor.set_auto_gain(False) # must turn this off to prevent image washout... sensor.set_auto_whitebal(False) # must turn this off to prevent image washout... clock = time.clock() roi = (0,0,160,120) # Note! Unlike find_qrcodes the find_apriltags method does not need lens correction on the image to work. # The apriltag code supports up to 6 tag families which can be processed at the same time. # Returned tag objects will have their tag family and id within the tag family. tag_families = 0 tag_families |= image.TAG16H5 # comment out to disable this family tag_families |= image.TAG25H7 # comment out to disable this family tag_families |= image.TAG25H9 # comment out to disable this family tag_families |= image.TAG36H10 # comment out to disable this family tag_families |= image.TAG36H11 # comment out to disable this family (default family) tag_families |= image.ARTOOLKIT # comment out to disable this family # What's the difference between tag families? Well, for example, the TAG16H5 family is effectively # a 4x4 square tag. So, this means it can be seen at a longer distance than a TAG36H11 tag which # is a 6x6 square tag. However, the lower H value (H5 versus H11) means that the false positve # rate for the 4x4 tag is much, much, much, higher than the 6x6 tag. So, unless you have a # reason to use the other tags families just use TAG36H11 which is the default family. def family_name(tag): if(tag.family() == image.TAG16H5): return "TAG16H5" if(tag.family() == image.TAG25H7): return "TAG25H7" if(tag.family() == image.TAG25H9): return "TAG25H9" if(tag.family() == image.TAG36H10): return "TAG36H10" if(tag.family() == image.TAG36H11): return "TAG36H11" if(tag.family() == image.ARTOOLKIT): return "ARTOOLKIT" while(True): clock.tick() img = sensor.snapshot() apriltags = img.find_apriltags(roi = roi)#, families=tag_families) if apriltags: for tag in apriltags: # defaults to TAG36H11 without "families". x = tag.cx()-tag.w()//2-5 y = tag.cy()-tag.h()//2-5 w1 = tag.w()+10 h1 = tag.h()+10 if x<0: x = 0 if y<0: y = 0 if w1>160: w1 = 160 if h1 >120: h1 = 120 roi = (x,y,w1,h1) print("roi:",roi) print("apriltag:",tag.rect()) img.draw_rectangle(tag.rect(), color = (255, 0, 0)) img.draw_cross(tag.cx(), tag.cy(), color = (0, 255, 0)) print_args = (family_name(tag), tag.id(), (180 * tag.rotation()) / math.pi) print("Tag Family %s, Tag ID %d, rotation %f (degrees)" % print_args) else: roi = (0,0,160,120) print("roi two :",roi) print(clock.fps())
Please give me some suggestion! Thanks a lot