Ch1:android Digital imaging:formats Concepts and optimization

Source: Internet
Author: User
Tags webp

Android Digital Image formats:lossless versus lossy

    1. gif is not recommended on Androd OS, cause is lossless , it doesn ' t away image data to achieve better compression results.
    2. JEPG is lossy digial image file format. It'll thorws away I Mage data in order ot achieve smaller file sizes.  and is unrecoverable after compression. So, make sure to save an orginal uncopressed image File
    3. andoid also support WEBP image format. 

The foundation of digital iamges:pixels and aspect ratio

    1. To found the number of pixels and image, simplely multiply the width pixels by height pixels.
    2. Aspec ratio would define how square or rectangular a image or display screen is.

The color of digital Imagel:color theory and color depth

  1. Color values for iamge pixels is defined by the amount of there different colors:red, green, and blue.
  2. The number of bits used to repersent coloer in a igital image was referred to as the color depth f the image.
  3. The lowest color depth exists in a 8-bit indexed color image, which has a CLOLR value. It used for GIF and PNG8 formats. The medium color depth image features a 16-bit color depth which contains 65536 colors. But it's not a supported by Android OS. A high color depth iamge features a 24-bit color. Include JPEG, Png,tiff and WebP.
  4. Using 24-bit color depth'll give you to the Hightset quality level. Since it ' s lossless, it has the highest quality compression.

Representing colors in Androd:hexadecimal Notation

    1. It's also important to note this in andoid. Color was not the only used in 2D digital iamgery. Also called Itmap imagery.
    2. #FFFFFF represents a color of whit. As each slot in this 24-bit hexadecimal representation represents on base value. To get the $2 slots for each RGB color would take.
    3. It's important to note this there is also a 32-bits image color depth whose data values were represented using an ARGB. Whre the A stand for Alpha. Which is a short for alpha channel.
      The Alpha stand for transparency.

Image compositing:alpha channels and Blending Modes

    1. Blending modes is implemented in Android using the Porterduff class.
    2. Some of Android ' s porterduff blending modes include ADD, screen, OVERLAY, darken, XOR, lighten, and MULTIPLY.

Digital Image masking:a Popular use for Alpha Channels

    1. One of the primary applications for Alpha channels are to mask out areas of an image for compositing.
    2. Masking is the process of cutting subject matter out of a image and placing it onto its own layer using an alpha channel.
    3. You can ' t really does effective image compositing without doing masking first, so it's an important area for graphics design ERs to master.
    4. Masking can be do by using selection tools and sharpening and blur algorithms

Ch1:android Digital imaging:formats Concepts and optimization

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