Summary of problems in developing a photo collection system

It has been almost two months since we reviewed this issue. Currently, the Windows version has been developed and the web version is being developed. From scratch, combined with previous experiences andCodeBy the way, some of the problems are listed and solved step by step.

1. Select the method and select supported by ATL ipicture.

2. Load a BMP/JPEG image and display it

3. Zoom in, zoom in, and drag

4. Implement Image Synthesis

5. Memory drawing to prevent flickering

6. Cut a part of the image and save it as BMP.

7. Cut a part of the image and save it as JPEG.

8. Cut a part of the image, set DPI to 300, and use GDI +

9. Synthesize another image in HDC

10. synthesize an image and make its background transparent.

11. HDC output text

12. Set the font for HDC output text

13.16bit and 32bit are compatible with transparent backgrounds.

14. Use DirectShow to process the WMD video.

15. Build the DirectShow environment and use the DirectX 9.0b version.

16. video capturing

17. Video filter and

18. Insert text and images into the video

19. Video Capture card is used. Currently, both USB and PCI plug-in cards are supported.

20. you need to add some basic video settings in the control, such as the video standard, video channel, and video format. In addition, different systems and hardware support different DirectShow methods, therefore, you need to determine which functions are supported by the system and hardware. You can refer to the well-known amcap in drectshowsdk for routine research.

21. after the video and graphics problems are solved, it is the specific problem of camera development. At this time, we need to study the camera's API. The API provided by the manufacturer will be provided to the routine and follow the routine to do it, no error. However, before development, we should first understand some terms of photography, such as white balance, awaf, flashing mode, exposure, and B-door shooting, what is the exposure gain and what is macro. If you have the conditions, you are advised to contact the photographer.

22. there are a lot of problems when you fail to take a photo at the scene. The most common problem is that you cannot focus and take a photo. Because we chose a single SLR, when you choose focus first, if it is a wall or a solid color, you cannot focus on imaging. You need to change the shooting mode. The shooting mode is still being studied, but it is mainly fixed in the camera.

23. the development of the web version, the development of the web version was very smooth, but not at all, first encountered a refresh problem, in the window version of ondraw, A firechange () only refresh once, in the IE container, it needs to be refreshed n times, and each time it is refreshed at a height of 150 pixels. This makes the originalProgramThere has been a small adjustment in the refresh.

24. The second problem is that there is no handle in the web space. That is to say, the container of the control is the IE display window. In this case, you need to get the size of the client to get the size of the entire IE. Therefore, you also need to adjust the window Program (you only need to add a panel ).

25. it is the problem of keyboard capturing. The keyboard capturing in Windows is different from that in IE. Windows can process wm_keydow or up information, but ie cannot, you need to set the ActiveX mode status when clicking. In this way, it can be captured in the corresponding message overload function. Overload

26. software driver deployment problems (different camera models), different from Windows

 

in windows, Delphi is used to call the ATL space. jquery is used to present the effect in web.