Online Tutorials for DVD Photo Slideshow
2. Something about digital photo and digital camera
With the development of the technology, people have more and more devices to take photos conveniently, such as camcorder, digital camera, cellular phone with camera, etc; moreover, the above devices are no longer need any roll films as the ordinary camera, and they help people store their sweet memory on their PC. Then, with the help of some photo editing software, the photos can be made into photo slideshow, which shows the photos in a brand new way.
2.1. The resolution of digital photos
In the digital world, "inches" don't exist, only pixels do. A pixel (short for "picture element") is the smallest unit in a computer image or display. Every image on your computer is made up of a colored grid of pixels. Digital images contain a fixed number of pixels per inch. You can increase the dpi (and therefore the resolution) by decreasing the dimensions of the photograph. For instance, if you have a photograph taken with a digital camera that is 1800 by 1200 pixels with a resolution of 72 dpi, you could obtain a 300-dpi resolution by decreasing the photo to a 6-by-4-inch size.
2.1.1. The Two Faces of Resolution
There are two basic ways the term resolution is used. One refers to the pixel count of an image. An image with lots of pixels is often called a "high resolution" image. But in other contexts, resolution refers to the density of pixels in a given linear area such as an inch. This "density" is expressed as ppi (pixels per inch) or dpi (dots per inch) and this density number is embedded invisibly in a bitmap image, as an instruction to output devices, such as a printers.
220.127.116.11 The differences between pixel count resolution and embedded resolution
Embedded resolution tells your printer how far apart to spread the pixels in a printed image. It determines how "fine grained" the printed image will look. It is completely independent of the pixel count of the image. A high-pixel-count image can have a low embedded resolution or vice versa. Embedded resolution is inversely proportional to the size of the printed image. Given the same pixel count, a high embedded resolution will result in a smaller printed image (the pixels are packed together more tightly), and a low embedded resolution will result in a larger image (the pixels are more spread out).
18.104.22.168. The differences between ppi and dpi
Actually, the two are the same, but the term ppi (pixels per inch) originated in the world of computers, and dpi (dots per inch) in the world or printing, however, today they are often used interchangeably.
2.1.2. The resolution setting should be chosen while taking a picture
It depends on what you want to do with the picture. Do you want to e-mail it to friends, post it on a Web site, make it your computer's wallpaper, print it as a 4" x 6" photograph, or create a poster-sized print? If you want to view the pictures on a computer monitor (such as those you send by e-mail or post to the Web), a low pixel-count setting is perfectly adequate. Because most people view images on monitors that display only 800 x 600 pixels, a low pixel-count image, such as a 600 x 400 photograph, will fill up most of their screen without running off the edges. A low pixel-count setting will also reduce the file size of the image and reduce time it takes others to download or display your image.
Printers, however, can print at much higher resolution than a typical computer screen. Images that you intend to print should be captured at a higher pixel-count setting.
- For a 2" x 3" print, the image dimensions should be 400 x 600 pixels minimum
- For a 4" x 6" print, the image dimensions should be 800 x 600 pixels minimum
- For a 5" x 7" print, the image dimensions should be 1000 x 1400 pixels minimum
- For an 8" x 10" print, the image dimensions should be 1600 x 2000 pixels minimum
If you are not sure what you want to do with your pictures the moment when you take a picture, to be safe, it's a good idea to set your camera to the highest resolution setting. You can always reduce the pixel-count of your image later for e-mailing or web publishing. (http://www.fotofinish.com/resources/centers/photo/resolution.htm )
Camcorders, or video camera-recorders, have been familiar for nearly 20 years to people. They can be used everywhere, such as school plays, sports events, family reunions and even births! When you go to a popular tourist spot, you are surrounded by them. Camcorders have really taken hold in many places, and this is because they are an extremely useful piece of technology that you can own for under $300 (or more than $100,000).
2.2.1. A brief introduction of camcorder
Generally speaking, a typical camcorder contains following two basic parts:
- A camera section, consisting of a CCD , lens and motors to handle the zoom, focus and aperture.
- A VCR section, in which a typical TV VCR is shrunk down to fit in a much smaller space.
The function of the camera component is to receive visual information and then interpret it as an electronic video signal. The VCR component is exactly like the VCR connected to your television , which receives an electronic video signal and records it on video tape as magnetic patterns (see How VCRs Work for details).
A third component, the viewfinder, receives the video image as well, so you can see what you're shooting. Viewfinders are actually small, black-and-white or color televisions, but many modern camcorders also have larger full-color LCD screens .
Based on all these elements, digital camcorders have an added component that takes
the analog information the camera has gathered and translates it to
bytes of data. Instead of storing
the video signal as a continuous track of magnetic patterns, it records the picture and sound
as 1s and 0s. Digital camcorders are so popular just because people can copy 1s and 0s very
easily without losing any of the information they've recorded. Analog information, on the other hand,
"fades" with each copy
-- the copying process doesn't reproduce the original signal exactly. Video information in digital form can also be loaded onto computers , where people can edit it, copy it, e-mail it and manipulate it .
CCD: the sensor in the camcorder and it is used to measure light with a half-inch (about 1cm) panel of 300,000 to 500,000 tiny light-sensitive diodes called photo sites.
How VCRs Work: VCR started to develop and popularize in the 1970s and 80s and it is a milestone in the history of the TV. For the first time, it gave people control of what they could watch on their TV sets. Prior to the VCR, there was no such thing as a video store. The other interesting thing about VCRs is how incredibly intricate and interesting they are inside. They are certainly the most complex mechanical systems most people own outside of their automobiles, yet VCRs can cost as little as $75! There are motorized tape loading and ejection systems, complex motorized tape paths, drum-mounted rotating read/record heads. Thus, to some extent, VCRs really are neat inside!
2.3. The Digital Camera
It is a great breakthrough to convert conventional analog information into digital information. This fundamental shift in technology totally changed the way in which we deal with visual and audio information -- it completely redefined what is possible. As one of the most remarkable instances of this shift, the digital camera is so truly different from its predecessor Conventional cameras which depend entirely on chemical and mechanical processes.
2.3.1. The characteristics of the digital camera
- Availability and flexibility
You can store unlimited number of pictures according to the storage space of your camera; moreover, it is possible to reshoot those pictures you are unsatisfied with.
- Surviving the destructive forces of time
The film used in conventional cameras would deteriorate and fade, however, digital images would never. A digital photo stored to disk will never fade, yellow, wrinkle, or scratch. The disk might fail, and that particular version may be lost, but if you can recover it as the original. With film, there is just one original. Every copy made from the original is just a copy, slightly inferior to the original. The digital photocopy is identical to the original, with no loss of quality.
- Speed and convenience
Before developing digital images, within minutes, you can access that image for a Web page, printing, or e-mail. The images can also be previewed on an LCD screen.
- Color and focus modifications
Digital photography puts you in charge of the darkroom. You can bring out highlights; adjust brightness, contrast, and saturation; adjust color; and crop your image.
- No electricity and no film
With the digital camera, it is not even necessary to need electricity to operate them. On the other hand, all digital cameras have a built-in computer, and all of them record images electronically. Instead of film, a digital camera has a sensor that converts light into electrical charges
Sensor: The image sensor employed by most digital cameras is a charge coupled device (CCD). Some cameras use complementary metal oxide semiconductor (CMOS) technology instead. Both CCD and CMOS image sensors convert light into electrons. The differences between the two main sensor types kick in:
- A CCD transports the charge across the chip and reads it at one corner of the array. An analog-to-digital converter (ADC) then turns each pixel's value into a digital value by measuring the amount of charge at each photo site and converting that measurement to binary form.
- CMOS devices use several transistors at each pixel to amplify and move the charge using more traditional wires. The CMOS signal is digital, so it needs no ADC.
2.3.2. . To take pictures by the digital camera
It takes several steps for a digital camera to take a picture. Here's basic procedure from beginning to end:
You aim the camera at the subject and adjust the optical zoom to get closer or farther away.
You press lightly on the shutter release.
The camera automatically focuses on the subject and takes a reading of the available light.
The camera sets the aperture and shutter speed for optimal exposure.
You press the shutter release all the way.
A processor interpolates the data from the different pixels to create natural color. On many cameras, it is possible to see the output on the LCD at this stage.
A processor may perform a preset level of compression on the data.
The information is stored in some form of memory device
2.3.3. Reviews of current popular digital cameras
There are five types of digital cameras in current market:
- Entry-level -- Basic digital cameras with few features and limited image quality. Priced from $50 - $200.
- Deluxe point-and-shoot -- These cameras offer more controls and produce better images than entry-level ones do. Priced from $200-$400. Printing is limited to 4x6 inches.
- Professional lite -- Features, quality, and ease of use make these cameras ideal for many different jobs, ranging from graphic and Web design to insurance and real estate. Priced from $300 - $800.
- Professional -- The best of digital cameras, producing images that meet or exceed the quality of film. Priced from $1500-$60,000.
- Gadget -- Toy cameras, and cameras that are built into computers. Priced from $10 - $200.
For more please visit: http://www.dpreview.com/reviews/
2.3.4. More about digital photograph
- Why is the photo so big on the computer, but when it prints, it's a lot smaller?
Generally speaking, the photo was taken at a high resolution setting on the camera. When you open it with some application such as Photoshop, it may look pretty large. The file's physical dimensions, however, maybe only something like 3"x5", which is what the printer will output. A lower resolution setting will result in a smaller size on the monitor, but the same physical size when the photo prints. Its quality will not be as good as a photo taken at a higher resolution setting, however.
An image's resolution is measured in dots per inch, or pixels per inch in the digital realm. Since a monitor never displays more than 72 dpi (dots per inch), photos that will never be used in print (such as for the Web or PowerPoint) are better saved down to 72 dpi from higher resolutions. You'll have a smaller file size and the files will load more quickly.
To see a file's physical size and resolution, open it in Photoshop and under the "Image" menu, go to "Image Size". It will bring up a window that will allow you to view and adjust the photo's physical size and resolution.
- How do I choose a digital camera?
Make sure what you want to do with your photographs. For example, will they be shared with family and friends, used professionally in a magazine or the Web, or needed at work or school? And what image quality do you need? What are you going to photograph? Do you need close-ups, action, or long-distance? How experienced are you? Do you want automatic settings or control over your camera's functions?
After you confirm mentioned-above matters, just ask the experienced one to help you.
- How do I transfer images?
The medium defines the ways you can transfer images from the camera to the computer. You can either connect the camera directly to a computer using a cable or you can remove the card or disk from the camera and pop it into a special drive. After downloading the images, erase the camera's storage medium, and you're ready to take more pictures.
Serial connections are very slow and require special software to download the images. Serial cables came with all the older cameras. They are plugged into the printer or modem port of the computer.
USB ( u niversal s erial b us) is a faster replacement for serial. If you are planning on using USB, you can look at the outside of the camera box for the USB symbol. Just plug the camera in and out of the USB port while the computer and camera are turned on, and open a photo application like iPhoto to download and view your pictures.