1. Introduction to Cameras Jim Rasche Samba Danfa Jaya Joseph 1

2. Outline Considerations in sensor selection: 1.How optics affect sensor selection 2.How an image is captured 3.Which type of camera sensor is best Setup and interactions: 1.File formats 2.Small sensors in embedded systems 3.Complex sensors in embedded systems 2

3. Aperture and Light Aperture: The size of the hole that lets light into a device controlled by shutter - This is not made to be controlled so it is important to know the range of the shutter when choosing - The more light coming into a sensor, the brighter the image can be http://loweryl.wordpress.com/2012/10/03/aperture-fstop- explained/ 3

4. Aperture and Depth of Field Controlling the focus of an image: Larger aperture = Narrow depth of field http://electronics.howstuffworks.com/cameras-photography/tips/aperture.htmhttp://markfrommeltphotography.blogspot.com/ 4

5. -Light from the lens falls onto a sensor array -Light at a specific point on the array passes through red, green, or blue filter on photodiode. From Light to Charge http://digital.pho.to/ 5

6. CCD vs CMOS CMOS pros: 1) 1/2 - 1/10 power of CCD 2) Single voltage input ~3.3V 3) Price and size CCD pros: 1) Signal / Noise ratio 2) Requires 15V, 3V, and -8V 3) Superior for low light http://www.electroiq.com/articles/stm/2011/03/cmos-image-sensors.html [http://cpn.canon-europe.com/content/education/infobank/capturing_the_image/ccd_and_cmos_sensors.do] 6

7. - The electric charge is converted into an analog voltage - It's amplified and sent to an Analog to Digital Converter (ADC) where it is digitized - The larger the charge, the larger the binary value readout - The file is a collection of numbers, representing location and brightness values for each square in an array Digitization http://carakerja-pengertian.blogspot.com/2011/03/cara-kerja-pengertian-kamera-digital.html 7

8. Image Formats: RAW and JPEG - Captured images usually defaulted to either RAW or JPEG formats - RAW: specific format (tied to camera manufacturer and sensor) - Preserves most amount of info about an image - JPEG: default format, most popular image format used - Easy to edit/manipulate http://www.slrlounge.com/raw-vs-jpeg-jpg-the-ultimate-visual-guide 8

9. Saving Files: RAW and JPEG - RAW image files have metadata attached to them -Two files are saved: one for the image data and another containing the camera settings -This allows for post production manipulation - When saving a JPEG file, all the information is saved in single file -Unchangeable 9

10. RAW file: 1.Can capture 4096 or more shades of color per pixel 2.No in-camera processing of images 3.Post production JPEG file: 1.Can only capture 256 shades of color per pixel 2.Internal processing causes loss in color 3.Lossy compression RAW vs JPEG 10

11. RAW vs JPEG: File Size 11

12. Examples of Cameras in Embedded Systems http://www.sketchinginhardware.com/toolkits/lego-mindstorms/http://brain.cc.kogakuin.ac.jp/~kanamaru/research/research-j.html http://diy-community.de/showthread.php?24138-Nachtsichtger%E4t 12

13. - Raw RGB565 output format only - Change frame rate ~15 - 30 fps - Color adjustment - Luminescence adjustment - Price: $9.95 https://www.sparkfun.com/products/8667 http://www.sparkfun.com/datasheets/Sensors/Imaging/TCM8230MD.pdf Toshiba TCM8230MD (A) Ver. 1.20 Example: Simple Sensors (CMOS Camera 640x480) 13

14. Toshiba TCM8230MD (A) Ver. 1.20 -2 voltage levels -8 data out pins -VD/HD lets user read image -I 2 C bus http://www.sparkfun.com/datasheets/Sensors/Imaging/TCM8230MD.pdf Interfacing with a Simple Sensor 14

15. Interfacing with a Simple Sensor Toshiba TCM8230MD (A) Ver. 1.20 2.8V 1.5V Power: -PVDD(Sensor Array) = 2.8V -IOVDD (I/O) = 2.8V -PVDD (other) = 1.5V -Usual current draw = 40mA 2.8V http://www.sparkfun.com/datasheets/Sensors/Imaging/TCM8230MD.pdf 15

16. Interfacing with a Simple Sensor Toshiba TCM8230MD (A) Ver. 1.20 2.8V 8 data out lines that transmit image data DOUT[7:0] Vertical/Horizontal pulse detection image assembly data http://www.sparkfun.com/datasheets/Sensors/Imaging/TCM8230MD.pdf 1.5V 16

17. Interfacing with a Simple Sensor http://www.sparkfun.com/datasheets/Sensors/Imaging/TCM8230MD.pdf 17

18. - Arduino compatible - Image manipulation library - Frame differencing - Color tracking - B/W video output - SD card storage - Developed and tested firmware - Price: ~$135.95 http://www.cmucam.org/projects/cmucam4 Example: Complex Cameras (CMU Cam) 18

19. -Attach camera onto Arduino -Include the CMUcam4.h in the Arduino IDE libraries Connecting to Controller http://www.cmucam.org/projects/cmucam4/wiki/Lextronic_Camera http://www.cmucam.org/boards/5/topics/113 19

20. Power the Board - Connect a 4-9V battery source capable of generating a 250 mA current http://www.cmucam.org/boards/5/topics/113 20

21. - 2 servo ports: Pan & Tilt for real world interaction http://www.cmucam.org/boards/5/topics/113 Servos http://hacknmod.com/hack/remote-controlled-pan-and-tilt- robot/ 21

22. Questions? http://xkcd.com/1014/ 22