Discards more data about colours than about brightnessNot all of the information in the original image is preserved –not the same as the originalDegrades the image qualityCompression is achieved by ‘forgetting’ certain details about the image, which the JPG will then try to fill in later when it is being displayedDegree of amount of information LOST (lossyness) can be varied by adjusting compression parameters. (controlled by you)Because image data is lost with each compression, work with the image in native format, and when ready with final product, save it as a .jpg fileSlide 38 of 48JPGQuality of image is inversely proportional to amount of compressionA higher image quality setting (has a lower compression value) results in less data being discarded.Original 0% Compression = 100% QualitySlide 39 of 48JPGCan you tell which image was saved with low quality, high compression in Photoshop?Slide 40 of 48JPGNo TransparencyNo AnimationNo InterlacingNo dithering (Question: why no dithering?)Slide 41 of 48PNGPronounced PINGCreated specifically because of licensing issues with GIFs in the 90sDoes LOSSLESS compressionMultiple versions of PNG◦PNG-8◦PNG-24◦PNG-32Slide 42 of 48PNG-8Similar to GIFOnly allows for 256 coloursAllows for 1 transparent colourStoring of colours is more efficient in PNG files than GIFS thus PNG-8 files might be SMALLER than their GIF counterparts (this is software dependent)
Subscribe to view the full document.
10/3/20198Slide 43 of 48PNG-24Allows for 24 bit colourSimilar to JPGs in terms of colour supportIt is LOSSLESS compression so JPG files will generally be smaller than the same image saved as PNG-24 file.Slide 44 of 48PNG-32Some PNGs have a 32-bit colour depthWhat are the last 8 bits for?◦Allows for transparencyon each pixel, withdifferent levels of opacity.Uses RGBA model (A stands for Alpha).Comparison of GIF, JPG, PNGGIFJPGPNG-8PNG-24Best ForLogos,Cartoons, DrawingsPhotographsLogos, Cartoons,DrawingsPhotographImages with aneed for transparencyType of CompressionLosslessLossyLosslessLosslessWell Supported in BrowsersAllAllAllNot on IE6TransparencyOne COLOUR onlyNOOne COLOURonlyVarying levels of opacity and transparencyAnimationYesNoNoNoDitheringYesNoYesNoInterlacingYesNoYesYesShape of imageMust be rectangularSlide 46 of 48File Size ComparisonThings to think about when working with images:Slide 48 of 48ReviewWhat formats would each of these images be best saved as?Left: JPG, Right: PNG or GIF
As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.
Temple University Fox School of Business ‘17, Course Hero Intern
I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.
University of Pennsylvania ‘17, Course Hero Intern
The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.
Tulane University ‘16, Course Hero Intern
Ask Expert Tutors
You can ask 0 bonus questions
You can ask 0 questions (0 expire soon)
You can ask 0 questions
(will expire )