I checked the links you provided and have the following remarks: That could explain the different numbers in “number of unique colors” I have. Now the picture has the file size kB. Where does the programm take something away so that the data amount decreases? One part orf my question is answered. The original PNG image is JPG compression is very efficient.
|License:||For Personal Use Only|
|iPhone 5, 5S resolutions||640×1136|
|iPhone 6, 6S resolutions||750×1334|
|iPhone 7, 7 Plus, 8, 8 Plus resolutions||1080×1920|
|Android Mobiles HD resolutions||360×640, 540×960, 720×1280|
|Android Mobiles Full HD resolutions||1080×1920|
|Mobiles HD resolutions||480×800, 768×1280|
|Mobiles QHD, iPhone X resolutions||1440×2560|
|HD resolutions||1280×720, 1366×768, 1600×900, 1920×1080, 2560×1440, Original|
I downloaded a picture from the Internet and saved as jpeg. Remains the part with the quality: Hello Bhikkhu Pesala, thank you very much for your response. I have a question regarding the image quality when using IrfanView, specifically in the following case: That could explain the different numbers in “number of unique colors” I have. It “breaks the image into 2×2 pixel blocks and only stores the average color information for each 2×2 pixel group” This means I only have a quarter of the colors of the original file.
I intentionally chose an area of the picture with wl, as areas with high contrast shows the most obvious JPG artefacts. Where does the programm take something away so that the data amount decreases?
Now the picture has the file size kB. The image has a file size of 5. The original PNG image is See my notes on Compression http: Let me try this Interestingly, the “Resolution”, “Original size”, “Current size”, “Print size from DPI “, “Original colors”, “Current colors” and “Required RAM memory” “The first line” information ” is exactly the same, but the “number of unique colors” and “required disk space “are different, so my question is: Since I had not set the correct filename yet, I opened the picture again later and stored under another name.
A search at the help of IrfanView and at Google brought the results that reduces the file size when using this setting. Hello Bhikkhu Pesala, thank you once again for your time and your help. One part orf my question is answered. I understand that reducing the quality is like zipping the file – only that you are not able to get the original file back.
The artefacts are just visible. No chroma subsampling https: I checked the links you provided and have the following remarks: Photos speicherg are just landscapes or seascapes will have even fewer artefacts at high compression settings.
But how is this technically possible when the resolution, current size and so on stays the same? What happens to the file when a storage with “quality 80” and no tick in “disable speicyert subsampling ie, use 1×1 “? JPG compression is very efficient.
Can you spot the difference between these three images? Disabling colour subsampling also save a lot of space, for very little loss of quality. Obviously some JPG artefacts are added, but only a close examination will spot the difference. You wrote that using higher percentage of Quality and using chroma subsampling will result in saving space.
I tried this and compared the information data of the files – still the same numbers except for “number of unique colors” and “required disk space”.
Unfortunately I found nowhere the indication, which is exactly the cause of the file size reduction.
speicyert The reason for the reduction of the file size is that the setting “Quality 80” and no “Disable color subsampling” ie 1×1 use was set when saving. Ich habe mir ein Bild vom Internet heruntergeladen und als Jpeg abgespeichert. What is compressed when I use lesser quality? Digital Image File Types Explained http: It doesn’t say why the file size gets smaller how is the smaller file size achieved?