0.91 beta 1 - Export to PCX - Bigger filesize with RLE compression?

Locked
User avatar
masterjp
Posts: 97
Joined: Fri Feb 13, 2009 4:37 pm
Location: Duesseldorf (Germany)

0.91 beta 1 - Export to PCX - Bigger filesize with RLE compression?

Post by masterjp » Fri Jun 08, 2018 5:17 pm

I tested the export dialog and selected the pcx format for export.
To test the RLE compression I recognize, that the RLE compression produce bigger files!
Is it correct? I though a picture compression reduce the filesize and do not increase it.

The upper picture shows the picture without RLE compression and the lower picture with RLE compression.

tst.jpg
OS: Windows 10 Pro x64 | XN-View 2.44 | XN-View MP 0.91 | Adobe Photoshop Elements 15 & Photoshop XXL

cday
XnThusiast
Posts: 1789
Joined: Sun Apr 29, 2012 9:45 am
Location: Cheltenham, U.K.

Re: 0.91 beta 1 - Export to PCX - Bigger filesize with RLE compression?

Post by cday » Fri Jun 08, 2018 5:40 pm

masterjp wrote:
Fri Jun 08, 2018 5:17 pm
I tested the export dialog and selected the pcx format for export.
To test the RLE compression I recognize, that the RLE compression produce bigger files!
Is it correct? I though a picture compression reduce the filesize and do not increase it.
I think the answer is simply that different types of compression are best suited to different types of image: colour mode (colour, grayscale or black and white) and different types of content: (photograph or line drawing, for example).

In this case RLE compression isn't suited to the complexity of your photo, but it could be very effective for a line drawing.

RLE Compression

User avatar
masterjp
Posts: 97
Joined: Fri Feb 13, 2009 4:37 pm
Location: Duesseldorf (Germany)

Re: 0.91 beta 1 - Export to PCX - Bigger filesize with RLE compression?

Post by masterjp » Fri Jun 08, 2018 5:48 pm

I thought so, but I was not sure. Thank you.
OS: Windows 10 Pro x64 | XN-View 2.44 | XN-View MP 0.91 | Adobe Photoshop Elements 15 & Photoshop XXL

User avatar
xnview
Author of XnView
Posts: 29927
Joined: Mon Oct 13, 2003 7:31 am
Location: France
Contact:

Re: 0.91 beta 1 - Export to PCX - Bigger filesize with RLE compression?

Post by xnview » Sat Jun 09, 2018 7:51 am

yes it's normal. RLE for PCX is not good for photography, only drawing
Pierre.

Locked