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  Frequently asked Questions (FAQ)

 
   
1. OV5680 Sensor Characteristics and RAW Bayer Format
 
  1.1 What is the RAW Bayer format and how it is different from standard RGB format?
  1.2 How the RAW Bayer format is different from the standard RGB format?
  1.3 How to get the standard RGB image from a Bayer RGB image?
  1.4 Is the Demosaicing process alone sufficient to get the good quality RGB image from the Bayer pattern sensor?
  1.5 How do we get the YUV image from Bayer pattern sensor?
   
2. e-CAM58_MI5680_MOD Camera Module
 
  2.1 Is the e-CAM58_MI5680_MOD support parallel data interface, instead of MIPI CSI-2?
  2.2 How do we implement Autofocus on e-CAM58_MI5680_MOD?
  2.3 Can I adjust the focus position of the e-CAM58_MI5680_MOD from my software (without any Autofocus algorithm)?
   
3. Evaluation Kit
 
  3.1 How can I evaluate the e-CAM58_MI5680_MOD?
  3.2 Do I need to buy the Denebola CX3 RDK to evaluate the e-CAM58_MI5680_MOD?
  3.3 If I have already got the Denebola CX3 RDK, what should I buy to evaluate e-CAM58_MI5680_MOD?
  3.4 I have bought the evaluation kit for e-CAM58_MI5680_MOD. But the kit is not working without the e-CAMView software installed?
   
4. e-CAMView and DirectShow based Application Development
 
  4.1 What is e-CAMView Application?
  4.2 What is DirectShow?
  4.3 What you mean by DirectShow filter? You refer Software ISP filter - what is it?
  4.4 I am not seeing the best image quality with e-CAMView and the evaluation kit for e-CAM58_MI5680_MOD.
  4.5 Will I get the source code of the Software ISP Filter?
  4.6 Can I get the source code of the e-CAMView application (without the Software ISP filter)
  4.7 I don't want to pay and license the e-CAMView. I want to build my own viewer application. What should I do?
  4.8 I don't want to use your evaluation kit for e-CAM58_MI5680_MOD. I want to get the RAW Bayer images directly from the sensor
  4.9 I don't want to use Denebola for evaluation. Do you have any other embedded platforms such as NXP/Freescale i.MX6 based Sabre Lite or Wandboard etc?
   
5. e-CAM58_MI5680_MOD Camera module customization
 
  5.1 I want to customize the e-CAM58_MI5680_MOD camera for my application. I want to use e-CAM58_MI5680_MOD in my project. But I want to
    customize the camera module pinout, dimensions and also the lens FOV. Can you supply customized versions of e-CAM58_MI5680_MOD?
  5.2 I want to use my own lens and I don't want to use the VCM AF lens at all. How can you help me on this?
   
 1. OV5680 Sensor Characteristics and RAW Bayer Format
  
1.1 What is the RAW Bayer format and how it is different from standard RGB format?
 
The RAW Bayer format is not the same as the standard RGB format. The RAW format refers to the raw output from the CMOS image sensor which is based on the Bayer Color Filter Array (CFA). Each pixel of the CMOS image sensor picks only one color (either Red or Green or Blue) of the incident light. The Bayer pattern is one type of color filter array, where 50% of the pixels respond to Green color, 25% of pixels respond to Red and remaining 25% to Blue color. The sensor has a micro-lens array that filters the respective color (Red or Green or Blue) for the respective pixels. Each pixel of the CMOS sensor array responds to one of these primary colors and the other two colors for the same pixel has to be interpolated.
 
     
         
  Figure 1: Bayer Pattern color filters passing the R,G and B colors
on to the respective pixels.
  Figure 2: Bayer Pattern of color filters on Image Sensor pixels  
 
The above picture shows the Bayer filter geometry. For more information please visit http://en.wikipedia.org/wiki/Bayer_filter
 
 
1.2 How the RAW Bayer format is different from the standard RGB format?
 
The RAW Bayer format contains one color information per pixel. That color information may be Red or Green or Blue, depending on the position of that pixel.

In the standard RGB format, each pixel contains all the three primary color information.
 
 
1.3 How to get the standard RGB image from a Bayer RGB image?
 
As explained in questions above, the Bayer RGB format contains only one color information per pixel. The other two color information has to be interpolated from the near pixels. There are various interpolation algorithms available and this process of obtaining RGB image from a Bayer pattern image is called as "demosaicing". There are lot of demosaicing algorithms each claiming its own advantages on image quality, noise, performance, chromatic noise reduction etc.
 
 
1.4 Is the Demosaicing process alone sufficient to get the good quality RGB image from the Bayer pattern sensor?
 
No, the demosaicing is just one of the processes, but the most important process affecting the image quality. All the processing required to create a RGB image out of Bayer pattern image is collectively known as Image Signal Processing (ISP). The ISP pipeline has multiple processes and demosaicing is one of critical process. Other processes include Color Correction, Dead/Bad Pixel correction, Black Level compensation, Noise reduction, Gamma correction etc. And the ISP can also have Auto Exposure, Auto White Balance, Auto focus etc.
 
 
1.5 How do we get the YUV image from Bayer pattern sensor?
 
The standard method to get the YUV image from Bayer pattern sensor is to first reconstruct the RGB image and then convert the RGB image to YUV image.
 2. e-CAM58_MI5680_MOD Camera Module
 
2.1 Is the e-CAM58_MI5680_MOD support parallel data interface, instead of MIPI CSI-2?
 
No, the e-CAM58_MI5680_MOD supports only MIPI CSI-2 interface. In fact, the OV5680 sensor also does not have parallel data interface.
 
 
2.2 How do we implement Autofocus on e-CAM58_MI5680_MOD?
 
The camera module does not have built-in Autofocus algorithm as the sensor is a RAW Bayer format sensor. However, the module has a VCM Autofocus motor which can be controlled from an external I2C lines. The Application Processor or DSP shall have the Autofocus algorithm that should move the VCM autofocus lens to support Autofocus.
 
 
2.3 Can I adjust the focus position of the e-CAM58_MI5680_MOD from my software (without any Autofocus algorithm)?
 
Yes, the VCM autofocus motor can be controlled through I2C interface. With this the lens focus can be manually adjusted. e-con supports this feature in the evaluation kit.
  3. Evaluation Kit
 
3.1 9. How can I evaluate the e-CAM58_MI5680_MOD?
 
e-con provides an evaluation kit for e-CAM58_MI5680_MOD camera. The kit is based on the Denebola CX3 RDK. The standard Denebola CX3 RDK comes with OV5640 sensor based camera module. e-con provides a small daughter board (part number: ACC-CX3RDK-5680) that enables the customers to evaluate our e-CAM58_MI5680_MOD camera module Denebola CX3 RDK. e-con provides the binary version of firmware which is to be loaded on the Denebola CX3 RDK. This firmware together with the e-CAM58_MI5680_MOD camera daughter board forms a complete evaluation kit and e-con supplies PC side software that demonstrates the features of e-CAM58_MI5680_MOD.
 
 
3.2 Do I need to buy the Denebola CX3 RDK to evaluate the e-CAM58_MI5680_MOD?
 
Yes. The evaluation kit for e-CAM58_MI5680_MOD consists of the following:

 
  1. Denebola CX3 RDK - The USB 3.0 UVC compliant Reference Design Kit. This kit comes with the OV5640 based camera module.
  2. ACC_CX3RDK_5680 - Accessory board for CX3 RDK that connects the e-CAM58_MI5680_MOD with the CX3 RDK base board. This accessory board contains the e-CAM58_MI5680_MOD module.
  3. RDK firmware binary customized for e-CAM58_MI5680_MOD
  4. PC side software for demonstrating e-CAM58_MI5680_MOD. This software contains the Software ISP (Image Signal Processing) library, which can be replaced or removed to access the raw image data from the camera.
 
 
 
3.3 If I have already got the Denebola CX3 RDK, what should I buy to evaluate e-CAM58_MI5680_MOD?
 
If you have already got the Denebola CX3 RDK, you just need to get the following from e-con to evaluate the e-CAM58_MI5680_MOD.

 
  1. ACC_CX3RDK_5680 - Accessory board for CX3 RDK that connects the e-CAM58_MI5680_MOD with the CX3 RDK base board. This accessory board contains the e-CAM58_MI5680_MOD module.
  2. RDK firmware binary customized for e-CAM58_MI5680_MOD.
  3. PC side software for demonstrating e-CAM58_MI5680_MOD. This software contains the Software ISP (Image Signal Processing) library, which can be replaced or removed to access the raw image data from the camera.
 
 
 
3.4 I have bought the evaluation kit for e-CAM58_MI5680_MOD. But the kit is not working without the e-CAMView software installed.
 
When you install the e-CAMView, you will be installing the Software ISP filter as well. As explained in earlier questions the e-CAM58_MI5680_MOD produces only RAW Bayer output. Without an ISP filter (such as the Software ISP that is supplied with e-CAMView), the RAW Bayer format video cannot be displayed by any other application. E-CAMView application converts this RAW Bayer output to YUV422 or RGB888 format and renders on the display.
  4. e-CAMView and DirectShow based Application Development
 
4.1 What is e-CAMView Application?
 
The e-CAMView application is a simple video viewer application built on DirectShow framework provided by Microsoft. This video viewer application is generic and can work with almost any UVC compliant video source such as integrated webcam etc. The e-CAMView application also supports all our USB UVC camera products.
 
 
4.2 What is DirectShow?
 
The Microsoft DirectShow application programming interface (API) is a media-streaming architecture for Microsoft Windows. Using DirectShow, your applications can perform high-quality video and audio playback or capture.

The DirectShow headers, libraries, SDK tools, and samples are available in the Windows SDK.
 
 
4.3 What you mean by DirectShow filter? You refer Software ISP filter - what is it?
 
The building block of DirectShow is a software component called a filter. A filter is a software component that performs some operation on a multimedia stream. For example, DirectShow filters can

 
  • read files
  • get video from a video capture device
  • decode various stream formats, such as MPEG-1 video
  • pass data to the graphics or sound card
 
Filters receive input and produce output. For example, if a filter decodes MPEG-1 video, the input is the MPEG-encoded stream and the output is a series of uncompressed video frames.
When we refer Software ISP filter, this filter receives the RAW Bayer format video and converts the same to YUV422 format video.
In DirectShow, an application performs any task by connecting chains of filters together, so that the output from one filter becomes the input for another. And hence, the DirectShow application is just a place holder where the filters are connected together to perform a particular job(s) and then offers handle to control the operation of these filters.
 
 
4.4 I am not seeing the best image quality with e-CAMView and the evaluation kit for e-CAM58_MI5680_MOD.
 
As mentioned earlier, the e-CAMView employs a basic implementation of Sofware ISP for converting the RAW Bayer output of e-CAM58_MI5680_MOD to YUV or RGB. This Software ISP filter is a very primitive implementation and contains just the bare minimal modules of the ISP pipeline and this is not optimized for the high quality Image Signal Processing.
 
 
4.5 Will I get the source code of the Software ISP Filter?
 
No, we don't provide the source code for the Software ISP filter.
 
 
4.6 Can I get the source code of the e-CAMView application (without the Software ISP filter)
 
Yes, you can license the source code of the e-CAMView application by executing a Source Code licensing Agreement with e-con Systems and paying an one-time royalty fee. Please contact sales@e-consystems.com to get the copy of SLA and the quotation for one-time license fee. Please note that e-con does not provide the source code of the Software ISP filter.
 
 
4.7 I don't want to pay and license the e-CAMView. I want to build my own viewer application. What should I do?
 

The first step is to download the Windows SDK which also contains the DirectShow SDK. Once you download and install the Windows SDK, then you can go the samples located at [SDK Root]\Samples\Multimedia\DirectShow folder. There are a number of sample applications that are provided by Microsoft as part of the SDK, which are used as a starting point for custom applications.

 

There are two capture applications that may be of interest for you.

 

The first sample application is called PlayCap, which is a very basic capture application that displays the video from the first capture device it locates in your system. This sample is available at the following location of your SDK installation:
[SDK Root]\Samples\Multimedia\DirectShow\Capture\PlayCap

 

The second capture sample shall be AmCap. This sample application demonstrates the following tasks related to audio/video capture:

 
  • Capture to a file
  • Live preview
  • Allocation of the capture file
  • Display of device property pages
  • Device enumeration
  • Stream control
 

 

This sample is available at the following location of your SDK installation:
[SDK Root]\Samples\Multimedia\DirectShow\Capture\AmCap

 

Both the samples are available with source code and you can use these samples to build your own application. For more information and help, please refer the SDK documentation or http://msdn.microsoft.com/en-us/library/windows/desktop/dd375454%28v=vs.85%29.aspx and http://msdn.microsoft.com/en-us/library/windows/desktop/dd375849%28v=vs.85%29.aspx

 
 
4.8 I don't want to use your evaluation kit for e-CAM58_MI5680_MOD. I want to get the RAW Bayer images directly from the sensor?
 
You can still use the Denebola CX3 RDK based evaluation kit along with the associated firmware binary. But instead of using e-CAMView, you can write your own DirectShow application to grab the RAW Bayer format video directly from the sensor. You can implement a grabber filter (a type of DirectShow filter) and grab the RAW Bayer images and you can do any processing.
 
 
4.9 I don't want to use Denebola for evaluation. Do you have any other embedded platforms such as NXP/Freescale i.MX6 based Sabre Lite or Wandboard etc?
 
As of now, we don't have support for any other embedded platform. But we can develop the driver for these embedded platforms on request. Please contact sales@e-consystems.com for getting the quote for driver development for any other embedded platform.
  5. e-CAM58_MI5680_MOD Camera module customization
 
5.1 I want to customize the e-CAM58_MI5680_MOD camera for my application. I want to use e-CAM58_MI5680_MOD in my project. But I want to customize the camera module pinout, dimensions and also the lens FOV. Can you supply customized versions of e-CAM58_MI5680_MOD?
 
Yes, we can customize the PCB, sensor orientation or even the flex PCB length/shape. These are minimal level changes. We can also replace or customize the lens for your application as well. All these customizations attract NRE charges. Please contact sales@e-consystems.com along with your customization request to get the quote for the same.
 
 
5.2 I want to use my own lens and I don't want to use the VCM AF lens at all. How can you help me on this?
 
We can customize the sensor PCB just to have the sensor and a S-mount lens holder and you can use your own M12 lens on this module.