Timeline for delete half transparent pixels in image
Current License: CC BY-SA 3.0
23 events
| when toggle format | what | by | license | comment | |
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| Feb 17, 2018 at 17:06 | comment | added | steros | Sorry I meant "without semi transparent pixels". Also I confirmed imgur converts the image and just removes all the half transparent pixels. | |
| Feb 17, 2018 at 17:02 | vote | accept | steros | ||
| Feb 17, 2018 at 17:02 | answer | added | steros | timeline score: 1 | |
| Feb 17, 2018 at 16:43 | vote | accept | steros | ||
| Feb 17, 2018 at 17:02 | |||||
| Feb 17, 2018 at 16:42 | comment | added | steros | It must have been converted, but I just found out that Photoshop can actually safe 8bit with semi transparent pixels. | |
| Feb 16, 2018 at 16:12 | comment | added | Jongware | Unfortunately that sample image either already is 8 bit RGBA, or my browser (checked Safari and Firefox) or imgur.com "helpfully" converts it ... | |
| Feb 15, 2018 at 7:58 | history | edited | steros | CC BY-SA 3.0 |
added example as requested
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| Feb 13, 2018 at 22:57 | comment | added | Jongware | If the OP can add a sample image to the question, I could take a look at writing up some script to handle this. | |
| Feb 13, 2018 at 20:41 | comment | added | Billy Kerr | @joojaa If there's a web tool that allows this, then perhaps you should add one of these as an answer. It might help the OP avoid having to delete the semi transparent pixels altogether. | |
| Feb 13, 2018 at 20:26 | comment | added | joojaa | @BillyKerr actually usr2564301 is right. However neither photoshop nor gimp support it. But all browser vendors do, if you try to open one of these pngs in Photoshop it will just fail spectacularly. And yes there are lots of free web compression tools that allow you to do this. And also many do some lossy compression thats almost invisible to human eye but much easier on the compression scheme. | |
| Feb 13, 2018 at 18:28 | comment | added | Billy Kerr | @usr2564301 I use GIMP too, you have to convert to Indexed mode to ouput a PNG8. Perhaps you have discovered a niche market for your software! | |
| Feb 13, 2018 at 18:25 | comment | added | Jongware | @BillyKerr: just try opening a bog standard PNG with alpha in Photoshop - it can't even do that properly 😄. But, no, unfortunately I don't have a good alternative suggestion. I've never used GIMP; it may do better. For low-level PNG processing I usually write my own software. | |
| Feb 13, 2018 at 17:48 | comment | added | Billy Kerr | @usr2564301 - "bad support" - perhaps, but just try getting Photoshop to output semi-transparency in a PNG8. It can't do it. It simply converts to Indexed colour. What software do you suggest? | |
| Feb 13, 2018 at 16:28 | comment | added | Jongware | @BillyKerr: Don't let the bad support in Photoshop (for example) confuse you! The official specification does not contain such a restriction at all: "For [indexed-colour], alpha is a series of values [...] Each entry indicates that the corresponding palette index has the specified alpha. [..] [A] tRNS chunk may contain fewer values than there are palette entries; the remaining values are assumed to be 255. When only palette index 0 need be made transparent, only a one-byte tRNS is required ..." (paraphrased, but do read the full text) | |
| Feb 13, 2018 at 16:15 | answer | added | Wolff | timeline score: 9 | |
| Feb 13, 2018 at 16:09 | comment | added | steros | I found this thread how get these pixels into a layer mask in photoshop. and it seems to work (but not 100% sure). But I fail to find a way to actually delete them smoothly. - forums.adobe.com/thread/739988​ | |
| Feb 13, 2018 at 15:58 | comment | added | Billy Kerr | @usr2564301 - nope. 8bit PNGs are indexed colour, just like GIFs. | |
| Feb 13, 2018 at 15:55 | comment | added | steros | I only have the original 16bit png. | |
| Feb 13, 2018 at 15:50 | comment | added | Wolff | Is the original image only one layer? Or do you have a mask which could be edited? | |
| Feb 13, 2018 at 15:48 | comment | added | Jongware | @BillyKerr: you are confusing it with GIF transparency. 8-bit palette also supports transparency which (1) can have another value than 100% and (2) can have more palette entries, each with a different transparency. | |
| Feb 13, 2018 at 15:46 | comment | added | Billy Kerr | The PNG8 format doesn't support multiple levels of transparency. It only has either totally opaque, or totally transparent pixels, no semi-transparency! PNG8 is a bit like a GIF, which also suffers from the same problem. | |
| Feb 13, 2018 at 15:42 | comment | added | Jongware | Are you throwing away the transparency on purpose? 8-bit PNGs also allow it. | |
| Feb 13, 2018 at 15:35 | history | asked | steros | CC BY-SA 3.0 |