For photos, JPEG is your choice. In this video, learn how photos are compressed and how you can adjust image quality.
- [Instructor] Now let's turn out attention…to photographic images.…The JPEG format stands for the name of the group…that designed it.…The Joint Photographic Experts Group.…This format has been around since 1992.…Like portable network graphics,…it allows an image to have over 16 million colors.…256 levels each for red, green, and blue.…Unlike the line art formats,…JPEG doesn't allow animation or transparent pixels.…The compression JPEG uses is very different from PNG or GIF.…
Let's look at a closeup of part of a photo.…All the colors there just different enough that the method…that line art uses for compression won't work here.…JPEG instead analyzes the pixels in groups…and uses a mathematical formula to find a set of factors…that best represent those pixels.…This formula's designed around the way…your eye perceives colors.…The JPEG file stores the factors, not the individual pixels.…When you display the image, the browser plugs the factors…back into the formula and creates a set of pixels,…because the formulas can't be a hundred percent accurate,…
AuthorJ. David Eisenberg
- Using the img element
- Resizing images
- Obtaining images for your website
- Image formats and when to use them
- Styling images with CSS
- Adjusting borders, margins, and padding
- Adding background images
- Testing screen resolutions
- Autonumbering figures with CSS
Skill Level Intermediate
Design the Web: Responsive SVG Imageswith Chris Converse22m 46s Beginner
1. Image Essentials
2. Image Formats
3. Images and CSS
4. Responsive Images
Next steps1m 19s
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