Uploaded PNG images are converted into JPEG now.

PeterK · 10 May 2018, 02:31

Is the forced image conversion from PNG into JPEG a new feature or a bug?

Some details are getting lost and JPEG artefacts are added. Not good if you want to explain or demonstrate small differences between two screenshots pixel by pixel.

daxb · 10 May 2018, 14:52

I uploaded a PNG screenshot and clicked on "Preview Post". Then on the attached PNG and it looks good. If there is a bug that converts PNG to JPG then it should be fixed. Investigation needed.

PeterK · 10 May 2018, 17:20

Today I noticed that it depends on the size of the uploaded image file. If a PNG is greater than 488.3 kB than it's converted into a JPEG and the extension changes, too. Don't know if that limit has already existed on the old server. I think that the free upload volume should be the only restriction. Maybe a requester could ask the user whether he wants to convert his images into the smaller JPEG format. If not, then the users sometimes has to cleanup his uploads.

DamienD · 10 May 2018, 17:32

Thread moved out of the "Off Topic" section where RCK will see it.

PeterK · 10 May 2018, 17:41

Thanks DamienD !

mark_k · 10 May 2018, 20:12

Not a proper solution, but before uploading PNGs you could try reducing file size by using a lossless recompressor/optimiser like PNGOUT. You'd be less likely to hit the 500,000-bytes limit then.

PeterK · 10 May 2018, 20:29

Thanks Mark,
usually I'm already using the highest PNG comression rate = 9 in IrfanView, but I just saw that it has also support for a PNGOUT plugin, although I won't expect more than a few percent size reduction. The PNGOUT plugin is only as a 32 bit version available, but I'm using IrfanView 64.

mark_k · 10 May 2018, 20:37

Sometimes you'd be surprised how much an improvement you can get, especially for images that have a limited palette.

PeterK · 11 May 2018, 01:00

With PNGGauntlet (PNGOUT included and updated) it takes very long to optimize some screenshots from WinUAE: 3-4.5 minutes. Ok, the size reduction looks quite good, up to 30 % less, but I can get 22-25 % already with IrfanView in less than a second, and then PNGOUT would only give me another 3.5-4.5 % better compression. I would do that only if size is a very important factor.

RCK · 11 May 2018, 10:44

Quote:

Originally Posted by PeterK

Today I noticed that it depends on the size of the uploaded image file. If a PNG is greater than 488.3 kB than it's converted into a JPEG and the extension changes, too. Don't know if that limit has already existed on the old server. I think that the free upload volume should be the only restriction. Maybe a requester could ask the user whether he wants to convert his images into the smaller JPEG format. If not, then the users sometimes has to cleanup his uploads.

Yep, this behavious was already here

I have raised up the size limit to 1MB for jpg / gif / png instead of 500k

RCK · 11 May 2018, 10:45

Quote:

Originally Posted by DamienD

Thread moved out of the "Off Topic" section where RCK will see it.

Thanks

Amiga1992 · 11 May 2018, 14:28

Quote:

Originally Posted by RCK

Yep, this behavious was already here

Why is the conversion necessary?

PeterK · 11 May 2018, 16:12

Quote:

Originally Posted by RCK

Yep, this behavious was already here

I have raised up the size limit to 1MB for jpg / gif / png instead of 500k

Maybe I never noticed this limit before, because in most cases I'm cutting out and uploading only the important parts of a screenshot.

Thank you RCK, now it's 100 % better than before!

Btw, with IE11 I still get these doubled line feeds in the editor, and I cannot click on smilies to insert them into the text. Only drag&drop works.

daxb · 11 May 2018, 16:14

IMHO automatic format conversion is not good. If the image size is to large then a message should inform the user about it like it is done with other filetypes.

DamienD · 11 May 2018, 16:17

Quote:

Originally Posted by PeterK

Btw, with IE11 I still get these doubled line feeds in the editor

Me too and with PMs

hipoonios · 12 May 2018, 19:18

Quote:

Originally Posted by PeterK

With PNGGauntlet (PNGOUT included and updated) it takes very long to optimize some screenshots from WinUAE: 3-4.5 minutes. Ok, the size reduction looks quite good, up to 30 % less, but I can get 22-25 % already with IrfanView in less than a second, and then PNGOUT would only give me another 3.5-4.5 % better compression. I would do that only if size is a very important factor.

Nice little tool! I compressed ~100 screenshots (320x256) in less than 30 secs and got much better results than the old method I used. Thanks

PeterK · 12 May 2018, 19:38

Hmm, I guess your optimizations are so much faster, because your small images will fit completely into the CPU cache unlike my 1280x800 screenshots. I have only a slow Mini-PC with 2x1MB cache.

hipoonios · 12 May 2018, 20:22

I tried compress 34 files in 1280x800 and it took longer (2 mins, 6 secs). I will use it mostly for 320x256 images, so no problem for me.

RCK should consider using PNGOUT for HOL. I did some tests and the size can be reduced 20%-40%.

PeterK · 12 May 2018, 20:33

Well, I see, your PC must be about 50 times faster than mine.

RCK · 14 May 2018, 17:09

Quote:

Originally Posted by DamienD

Me too and with PMs

Sorry dudes, but you will have to find me a Virtual Machine with a version of IE11 with the problem because I can't debug it if I can't reproduce it

10 May 2018, 02:31	#1
PeterK Registered User Join Date: Apr 2005 Location: digital hell, Germany, after 1984, but worse Posts: 3,365	Uploaded PNG images are converted into JPEG now. Is the forced image conversion from PNG into JPEG a new feature or a bug? Some details are getting lost and JPEG artefacts are added. Not good if you want to explain or demonstrate small differences between two screenshots pixel by pixel.

10 May 2018, 20:29	#7
PeterK Registered User Join Date: Apr 2005 Location: digital hell, Germany, after 1984, but worse Posts: 3,365	Thanks Mark, usually I'm already using the highest PNG comression rate = 9 in IrfanView, but I just saw that it has also support for a PNGOUT plugin, although I won't expect more than a few percent size reduction. The PNGOUT plugin is only as a 32 bit version available, but I'm using IrfanView 64. Last edited by PeterK; 10 May 2018 at 20:39.

12 May 2018, 20:22	#18
hipoonios Amiga Hardcore Gamer Join Date: Apr 2005 Location: Sweden Age: 46 Posts: 1,207	I tried compress 34 files in 1280x800 and it took longer (2 mins, 6 secs). I will use it mostly for 320x256 images, so no problem for me. RCK should consider using PNGOUT for HOL. I did some tests and the size can be reduced 20%-40%. Last edited by hipoonios; 12 May 2018 at 20:29.

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10 May 2018, 14:52	#2
daxb Registered User Join Date: Oct 2009 Location: Germany Posts: 3,303	I uploaded a PNG screenshot and clicked on "Preview Post". Then on the attached PNG and it looks good. If there is a bug that converts PNG to JPG then it should be fixed. Investigation needed.

10 May 2018, 17:20	#3
PeterK Registered User Join Date: Apr 2005 Location: digital hell, Germany, after 1984, but worse Posts: 3,365	Today I noticed that it depends on the size of the uploaded image file. If a PNG is greater than 488.3 kB than it's converted into a JPEG and the extension changes, too. Don't know if that limit has already existed on the old server. I think that the free upload volume should be the only restriction. Maybe a requester could ask the user whether he wants to convert his images into the smaller JPEG format. If not, then the users sometimes has to cleanup his uploads.

10 May 2018, 17:32	#4
DamienD Banned Join Date: Aug 2005 Location: London / Sydney Age: 47 Posts: 20,420	Thread moved out of the "Off Topic" section where RCK will see it.

10 May 2018, 17:41	#5
PeterK Registered User Join Date: Apr 2005 Location: digital hell, Germany, after 1984, but worse Posts: 3,365	Thanks DamienD !

10 May 2018, 20:12	#6
mark_k Registered User Join Date: Aug 2004 Location: Posts: 3,333	Not a proper solution, but before uploading PNGs you could try reducing file size by using a lossless recompressor/optimiser like PNGOUT. You'd be less likely to hit the 500,000-bytes limit then.

10 May 2018, 20:37	#8
mark_k Registered User Join Date: Aug 2004 Location: Posts: 3,333	Sometimes you'd be surprised how much an improvement you can get, especially for images that have a limited palette.

11 May 2018, 01:00	#9
PeterK Registered User Join Date: Apr 2005 Location: digital hell, Germany, after 1984, but worse Posts: 3,365	With PNGGauntlet (PNGOUT included and updated) it takes very long to optimize some screenshots from WinUAE: 3-4.5 minutes. Ok, the size reduction looks quite good, up to 30 % less, but I can get 22-25 % already with IrfanView in less than a second, and then PNGOUT would only give me another 3.5-4.5 % better compression. I would do that only if size is a very important factor.

11 May 2018, 16:14	#14
daxb Registered User Join Date: Oct 2009 Location: Germany Posts: 3,303	IMHO automatic format conversion is not good. If the image size is to large then a message should inform the user about it like it is done with other filetypes.

12 May 2018, 19:38	#17
PeterK Registered User Join Date: Apr 2005 Location: digital hell, Germany, after 1984, but worse Posts: 3,365	Hmm, I guess your optimizations are so much faster, because your small images will fit completely into the CPU cache unlike my 1280x800 screenshots. I have only a slow Mini-PC with 2x1MB cache.

12 May 2018, 20:33	#19
PeterK Registered User Join Date: Apr 2005 Location: digital hell, Germany, after 1984, but worse Posts: 3,365	Well, I see, your PC must be about 50 times faster than mine.

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