Argb
One typeColor mode, That isRGBColor mode attaches alpha (TransparencyChannels are commonly used in the storage structure of 32-Bit Bitmap.
Argb --- Alpha, red, green, blue.
Alpha-image Channel
IfGraphics cardWith 32-bitBus, The attached 8-bitSignalIt is used to save invisible transparency signals for processing convenience.Alpha Channel. A white Alpha pixel is used to define an opaque color pixel, while a black Alpha pixel is used to define a transparent pixel.GrayscaleUsed to define translucent pixels.
Rgba
Rgba is the color space that represents red (red) Green (green) blue (blue) and Alpha. Although it is sometimes described as a color space, it is actually only the additional information attached to the RGB model. The color used is RGB and can belong to any RGB color space. However, Catmull and Smith proposed this indispensable Alpha value between 1971 and 1972, this makes Alpha rendering and Alpha synthesis possible. The author named Alpha as the source of the classic linear interpolation equation α.
+ (1-α) B uses the Greek letter.
alpha channel is generally used as the opacity parameter. If the alpha channel value of a pixel is 0%, it is completely transparent (that is, invisible ), the value 100% means a completely opaque pixel (a traditional digital image ). The value between 0% and 100% enables pixels to be displayed through the background, just like glass (translucent). This effect is not possible with simple binary transparency (transparent or opaque. It makes digital synthesis easy. The alpha channel value can be expressed as a percentage, an integer, or a real number ranging from 0 to 1 as in the RGB parameter.
Sometimes it is also writtenArgb(Like rgba, but the first data is alpha), yesMacromediaThe term used by the product. For example, 0x80ffff00 is 50% transparent yellow, because all parameters are expressed in the range from 0 to 255. 0x80 is 128, which is about half of 255.
PNGIs an image format that uses rgba.