Photoshop .BMP partial screenshot not resolved


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7 hours ago, nogain said:

Yes, all .bmp open in Photoshop.   Even Maxthon's "save as... image" .bpm works.   Only Maxthon's screenshot does not open. 

I don't have photoshop, but it works fine in paintshop

sigmax2.png

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14 hours ago, nogain said:

Yes, I konw, but not in photoshop, since Maxthon V4   :) 

 

12 hours ago, nogain said:

Yes, all .bmp open in Photoshop.   Even Maxthon's "save as... image" .bpm works.   Only Maxthon's screenshot does not open. 

Try renaming the images.

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It seems it's because Maxthon isn't saving as a BMP when using MXsnap. Even though the extension is BMP it's actually saving as a PNG.

Seems most other programs ignore the file type and open it based on the file header (possibly?), while your version of PS is trying to open it as a BMP when it's not, so you get the error.

What version of PS are you running?

But the file is definitely not a BMP. More than likely a bug and the wrong encoder is being called.

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1 hour ago, 7twenty said:

It seems it's because Maxthon isn't saving as a BMP when using MXsnap. Even though the extension is BMP it's actually saving as a PNG.

Seems most other programs ignore the file type and open it based on the file header (possibly?), while your version of PS is trying to open it as a BMP when it's not, so you get the error.

What version of PS are you running?

But the file is definitely not a BMP. More than likely a bug and the wrong encoder is being called.

for my understanding : why do you say it's a .png ?

my own screencapture using maxsnap, saved as "test.bmp", and opened in paintshop ; properties : looks like it's really a .bmp

bmp.png

sigmax2.png

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54 minutes ago, -ody- said:

for my understanding : why do you say it's a .png ?

1 / the size. BMP's (depending on type) generally don't have any compression so are rather large. So in your image, the size on disk/RAM should be the same meaning there's some sort of compression going on.

2 / the file is showing up as PNG encoded in other image viewers.

3 / the file header is showing that it's a PNG, not a BMP file.

4 / file extensions can be changed to anything. In this case it's being encoded as PNG but slapped with a BMP extension. Which is why you need to be wary of opening suspect files. The filename might be Cute_cat.mp4, but could actually be an EXE file infected with a virus.

I'm actually quite surprised that Photoshop won't open it if it doesn't match the extension type. Not sure if it's an older version which has since been fixed. Or possibly a safety feature.

You can test this as well, rename the file to PNG and see if photoshop still complains about it.

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29 minutes ago, 7twenty said:

You can test this as well, rename the file to PNG and see if photoshop still complains about it.

Too lazy to d/load PS, but renaming a BMP saved image to png opened without issue in Irfan view.

Edit: So did a bmp saved with Edge and renamed to png.

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36 minutes ago, PHYR said:

Too lazy to d/load PS, but renaming a BMP saved image to png opened without issue in Irfan view.

Edit: So did a bmp saved with Edge and renamed to png.

Sort of a pointless test seeing as those programs aren't the ones with the issue.

Quote

but renaming a BMP saved image to png opened without issue in Irfan view.

Because it is a PNG. If you rename it back to BMP it will give you an error saying it has the wrong extension and should be PNG.

 

All of the above points to MX saving the file incorrectly. Also Photoshop only using the extension to determine filetype, instead of actually checking the file header to see what it's supposed to be.

On 25/07/2017 at 5:03 AM, PHYR said:

Partial BMP opens fine in irfan view

Just noticed you did this... very odd. No error?

What does it show when you press the "I" key when displaying that image?

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6 hours ago, 7twenty said:

Sort of a pointless test seeing as those programs aren't the ones with the issue.

Because it is a PNG. If you rename it back to BMP it will give you an error saying it has the wrong extension and should be PNG.

 

All of the above points to MX saving the file incorrectly. Also Photoshop only using the extension to determine filetype, instead of actually checking the file header to see what it's supposed to be.

Just noticed you did this... very odd. No error?

What does it show when you press the "I" key when displaying that image?

It's a bmp image compressed with png.

 

MaxthonSnap20170729100916.jpg

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Without turning this into a history and info on BMP files thread, from wikipedia:

Compression[edit]
Indexed color images may be compressed with 4-bit or 8-bit RLE or Huffman 1D algorithm.
OS/2 BITMAPCOREHEADER2 24bpp images may be compressed with the 24-bit RLE algorithm.
The 16bpp and 32bpp images are always stored uncompressed.
Note that images in all color depths can be stored without compression if so desired.

1 / refers to images with 16 or 256 colour palettes - MX doesn't create these files
2 / the file created isn't using RLE compression as shown in your image
3 / stipulates that it must be uncompressed, and is when using the "save page as image" option
4 / confirms the above

But as noted, seeing as the "save page as image" option uses the correct format, it doesn't make sense why MXsnap would do it differently.

And more to the point, the header of the file is clearly PNG - this states what the file type is, not the compression type or otherwise. Compare both files in a HEX editor and against this image and you'll see why it's a wrongly named PNG rather than a PNG encoded BMP (which i'm pretty sure isn't a thing)

And another test:
Rename the "BMP" file to something random - image.x212423
Open the file in MX5 > rightclick > Properties
You'll see the Type is image/png, not image/bmp which is what it should be if it was infact a BMP file.
If you change the extension to any known extension (GIF/PNG/BMP/TIF/TGA/PCX), maxthon will always show whatever the extension is, which doesn't mean anything.

So MX5 (and it seems many other programs) will check the extension and assume that's what it is. If it can't figure out the extension then it actually checks the file or tries multiple ways to open it, at which point it will show the true file format.

I'd love to read some documentation on PNG encoded BMP's if it's actually a thing, seeing as i've never known that to be the case. But given all the above i'm 100% certain it's an error (wrong encoder being called), not some weird file format.

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I tested the thing with Photoshop CS2 and CS5.   As you said, if the file is renamed from .bmp  to  .png it is opened correctly.  So it's a .png, you're right. I would like a .bmp (because uncompressed) as well as created by "save as... image" Maxthon's function...   !

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On 8/6/2017 at 0:54 PM, -ody- said:

not sure why this thread was marked as resolved as it is not : renaming the file to png is only a workaround.

Bugsir could you take a look at this please ?

We have reported this issue to the dev team and are waiting for their confirmation and solution now.

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  • 3 weeks later...
22 minutes ago, 7twenty said:

Apparently this was fixed in 5.1.1.1000 " -Fixed the issue of the screenshot saved in BMP format can not open by Photoshop", but i'm still getting the same issue.

Hi Rob, could I know the version of your Photoshop? I tried on CC2017&CS5, both ok.

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Just now, BugMiss006 said:

Hi Rob, could I know the version of your Photoshop? I tried on CC2017&CS5, both ok.

Not using photoshop. Using Irfanview to check the file information, and it's still showing it as a PNG-zip compressed file.

Unless a different method is being used that i'm not aware of. If it's now working in PS then I guess it's not an issue, but I still don't think the files being created are actual BMP's as when saving a webpage using the main menu option.

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2 hours ago, 7twenty said:

Not using photoshop. Using Irfanview to check the file information, and it's still showing it as a PNG-zip compressed file.

Unless a different method is being used that i'm not aware of. If it's now working in PS then I guess it's not an issue, but I still don't think the files being created are actual BMP's as when saving a webpage using the main menu option.

It's odd...because when I opened the partial screenshot in Irfanview and checked image properties, there's no compression information.

image_info.bmp

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14 hours ago, PHYR said:

7twenty, you are saving it as a bmp, right? Otherwise it defaults to saving as png.

Definitely. Extension is correct, still get the warning error saying it's named wrong. but...

Interestingly, on a clean portable version it seems to work fine, but not on my everyday portable version of MX which includes my userdata. Not sure why something like this would or should be affected by any userdata?!

Anyway, based on the fact that the clean version works fine I think we can mark this as resolved and move on.

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