I work with grayscale images converted by the batch processing tool. Some of the images are interpreted as color when I open the Paint tool color dialog. The batch processing is always set to 256 colors and always convert to "grayscale". How can I correct this to keep the image grayscale at all times?
Announcement
Collapse
No announcement yet.
Grayscale image is designated as color by the Paint tool
Collapse
X
-
Setting the 256 colors is unnecessary, conversion to grayscale produces 256 "colors" anyway.
What image format do you use? Are the pictures interpreted as grayscale, when you open them in IrfanView before using the Paint tool?My system: IrfanView 4.62 64bit, Windows 10 22H2, Intel Core i5-3570, 16GB RAM, NVidia GTX 1050Ti 4GB
-
Originally posted by JendaLinda View PostWhat's your exact conversion settings? I've tested batch conversion to grayscale PNG and it worked for me.
The cause of the problem seemed to be the 'Colour depth group' in the advanced settings. If enabled, even with 256 colour depth, it generates inconsistent results. I will bring it to the attention of Irfan.Irfanview 4.54, Win 10 Pro 64bit 16gb RAM, Intel UHD graphics
Comment
-
Originally posted by JendaLinda View PostConversion to grayscale will actually convert the picture to 256 colors (256 shades of gray), so there's no need to specify the 256 color depth.Irfanview 4.54, Win 10 Pro 64bit 16gb RAM, Intel UHD graphics
Comment
-
Originally posted by ineuw View PostJendaLinda, again thanks and consider the issue resolved. BTW, do you know of any documentation about the advanced options in Batch processing? I found nothing.Before you post ... Edit your profile • IrfanView 4.62 • Windows 10 Home 19045.2486
Irfan Paint • Irfan View Help • IrfanPaint Help • Riot.dll • More Skins • FastStone Capture • Uploads
Comment
-
Originally posted by Bhikkhu Pesala View PostThere is some documentation on my Help page. It is by no means comprehensive. There are a lot of options.
The question omitted in my initial post was, if Floyd-Steinberg dithering would improve the quality of a grayscale image? If yes, then I will test the custom resolution with 256 and see if the color conversion problem returns. And, in case Floyd-Steinberg dithering makes no difference, then I will the group disabled.
My focus here is only on grayscale because the source material is also grayscale. I was hoping to improve the quality of my reproductions. Irfanview goes a long way in helping me understand a lot.Irfanview 4.54, Win 10 Pro 64bit 16gb RAM, Intel UHD graphics
Comment
-
Originally posted by JendaLinda View PostFloyd-Steinberg dithering has nothing to do with conversion to grayscale.
- After numerous tests, I found the problem. All images .jpg or .png converted to grayscale end up as grayscale 100% of the time.
- It's after editing and saving the images that the Paint tool reverts to the colour palette. It is then that I must select Image\Convert to Grayscale from the menu to revert the document to grayscale. Using Ctrl+G does not always work.
- Furthermore, this change always occurs when an image is re-saved several times.
- If the image only had a minor change and saved, it remains grayscale.
Irfanview 4.54, Win 10 Pro 64bit 16gb RAM, Intel UHD graphics
Comment
-
Originally posted by ineuw View Post- It's after editing and saving the images that the Paint tool reverts to the colour palette. It is then that I must select Image\Convert to Grayscale from the menu to revert the document to grayscale. Using Ctrl+G does not always work.
My system: IrfanView 4.62 64bit, Windows 10 22H2, Intel Core i5-3570, 16GB RAM, NVidia GTX 1050Ti 4GB
Comment
Comment