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Problem with resizing png images

Posted: Fri Mar 22, 2019 6:19 pm
by bunak
Hi
I want to reduce the size of png-images. But Executing a command with the following options horribly distorted images.
nconvert.exe -ratio -resize 500 0 -o "D:\Imgs_resize\%" "d:\Imgs\*.png"
Why is the image so bad?

There are examples of bad images in attached files with "_res" in the end

Re: Problem with resizing png images

Posted: Sat Mar 23, 2019 3:57 pm
by cday
bunak wrote:
Fri Mar 22, 2019 6:19 pm
I want to reduce the size of png-images. But Executing a command with the following options horribly distorted images.

Code: Select all

nconvert.exe -ratio -resize 500 0 -o "D:\Imgs_resize\%" "d:\Imgs\*.png" 
Why is the image so bad?

There are examples of bad images in attached files with "_res" in the end

The code in the help file for the resize option is:

Code: Select all

-resize w h      : Scale width-height
            w h can be percent (ex: -resize 100% 200%)
So you are resizing to a height of 0 pixels ??

Re: Problem with resizing png images

Posted: Sun Mar 24, 2019 8:07 am
by xnview
if you means bad quality, you need to resize in greyscale and not in binary, so please add before -resize

Code: Select all

-grey 256

Re: Problem with resizing png images

Posted: Mon Mar 25, 2019 8:32 am
by bunak
xnview wrote:
Sun Mar 24, 2019 8:07 am
if you means bad quality, you need to resize in greyscale and not in binary, so please add before -resize

Code: Select all

-grey 256
Thank you. Your recommendation helped.

Re: Problem with resizing png images

Posted: Mon Mar 25, 2019 8:34 am
by bunak
cday wrote:
Sat Mar 23, 2019 3:57 pm
So you are resizing to a height of 0 pixels ??
It is resize Image correctly with option -ratio