發表文章

目前顯示的是 8月, 2017的文章

OpenAlpr with webcam on Pi3

圖片
Last time I made an installation on Pi with 16GB microSD card on Pi3. it's tested with a stored jpg...result is good... Now I wish to make it works with SUB webcam I have on hand, which is a Logitech.. after plug in: it's detected, and works as a USB Class Video as ttyvideo0 INSTALL FSWEBCAM First, install the  fswebcam  package: sudo apt - get install fswebcam then test it: fswebcam image . jpg I got a black screen....something need to be done... not sure what error is this: GD Error: gd-jpeg: JPEG library reports unrecoverable error: Not a JPEG file I found a reason here: https://forum.arduino.cc/index.php?topic=253571.0 the problem was the frames. The camera gives black because it cant take a picture with one frame. You have to: 1)skip the first frames with the -S 10 2)or take the pictures with more frames -F 10 (range 1-255) 255 is slow 3) or give more power to camera (usb hub) so this can give a normal picture.   XD Code:  [Select]

Pi image need to be shrink down....

I used to use same mark of micro sd card, but recently for a copy to different mark but same size sd card, I met big trouble. I used to use win32 disk image writer, to read out .img file from a BBB or Pi micro sdcard. I usually use sandisk 8G C4, same one for the new ones. This time, when I wish to write a img file that I read out from a 16GB micro SD card to a sandisk ultra 16GB, I got error that new card does not have enough space. a little bit short. the sd is shown about 14.6GB search on net, there are problem like this. some say, it's because card maker use 1000 for K, but computing system use 1024 as K. I believe this is so so stupid. there is some way to shrink down the image, so that you can cross this stupid thing. But none can work in windows. it has to be done in linux. Since I don't have linux PC on hand, the easier way: I go for a kingstone Class4 16GB, once I put it in the windows, the capacity is slightly higher than sandisk ultra 16GB, about 15GB.