Bethanie

[bethanie]

Hi there

I am an illustrator and I use only graphite pencil (no color) to do traditional drawings. I have started the Affinity Photo trial to simply try and make the backgrounds clean and white and maybe enhance the contrast, that's it. I have watched many videos and tutorials but I can't get the hang of it. If it's a simple object, it's ok; but if there is shading, I don't know how to make the paper underneath, clean and white. Please help!! The motorbike is an example of something I want to edit, literally just make the background paper really white without touching the pencil. 

Bethanie

[jmwellborn]

On 2/18/2020 at 1:51 PM, smadell said:

If you are doing the watercolor directly in Affinity Photo, then the suggestion by DWright would seem to be the best one. However, if you are trying to get rid of an "almost white" background in an existing image, your best option might be using Blend Ranges. (1) Open the image in Photo; (2) Put a Fill Layer below it – I've used Red for best visualization; your choice of color will depend on the colors already in your image; (3) Open the Blend Ranges for the image (not the fill layer) and set them to something like what's shown in the screenshot below. I've set everything to be visible on my painting layer, up to a luminosity of 98%. Above that luminosity level, the painting layer goes from completely visible (at 98% luminosity) to completely transparent (at 100% luminosity). Sliding the node at 98% back and forth will let you see what parts of the painting are being affected, since the Fill Layer will show from below in those areas; (4) Delete, or Hide, the Fill Layer. Or, change the Fill color to pure white.

Then, you can print onto your paper and the areas that were originally "almost white" should now be transparent (or pure white, if you changed the Fill color), and should transition from opaque to transparent/white smoothly rather than abruptly.

@bethanie  Welcome to the forums!!   Perhaps this process might help you.  By the way, when you enter a title for a forum entry, it is not meant to be our names or titles (Dr. or Ms. or Gen.) but a subject that will attract helpers.  This came from a topic related to  True White Background Color.   I do hope this may help you.

[kirkt]

Hi @bethanie - to bring the white paper background to solid white and to add contrast to the image, you need to set your white and black points to get the effect you desire.  In the first attached screenshot, take a look at the histogram of your image.  The large peak on the right of the histogram at "a" is all of the near-white pixels of the paper background and its texture.  The large gap at the left of the histogram at "b" is telling you that there are no pure black or near black pixels in the image.  To push the near-white pixels of the paper and its texture to white, you want to set the white level of the image to an RGB value less than those pixels - this will make the near-white background completely white and remove the texture of the paper as well.  It will also add contrast.  To add more contrast, set the black level to something lighter than pure black - this will make the lighter black tones darker.  

There are several ways to do this, but the most straightforward way is with a Levels adjustment layer.  In the second screenshot, I moved the white point in to 84% of pure white and moved the black point to 21% of pure black.  This squeezes out the near-white pixels of the background to pure white and pushes the lighter dark tones closer to pure black.  You can also use the Gamma slider to control the midtones.  Take a look at the histogram of the after image  -all of those near-white pixels are now clipped to pure white and the light black pixels are now near the left edge of the histogram. This is also known as histogram stretching.

If the effect is too harsh and starts to bleed into the pencil shading, you can back the white and black levels off back toward their respective original values (100 and 0).

Kirk 

[kirkt]

Here is a more gentle treatment of the image with gentler black and white points and some adjustment of gamma to retain the soft pencil sketch look.

kirk

 

[bethanie]

Hi Kirk, 

Thank you so much! This was really helpful! One last thing though, after I had made the adjustments exactly as you said, I wanted to make the background pure white and retain a little more of the pencil shading around the middle of the picture. I used the selection tool to add/subtract the areas I wanted and refined it, so in theory, the parts that should be white are now ready. As you can see from the image, everything I want in white has been "checker boarded"; only now, I can't work out how to get rid of this checkerboard and actually make it white. I've tried what feels like everything, and even when I export it as a png, it comes up as a weird grey tone (see below). If you have any ideas, please let me know, I know I'm so close! 

Thanks

Bethanie

 

[firstdefence]

Select the top three layers and group them, this should isolate the levels adjustment so it doesn’t affect the Pixel layer at the bottom.

Another option would be to make the levels adjustment layer a child of the background layer so that it only affects the background layer and nothing else you do that by dragging the levels layer over the background layer and move the cursor over to the right until you see an indented blue bar

The mask could also be assigned to the background layer as a mask by right-clicking on the mask layer and selecting Mask to below.

Make levels a child, notice where the faded icon is to get the indented blue line indicating it will become a child layer.

 

Assign mask to layer, notice the short vertical blue line next to the layer icon indicating the layer will become a mask, the same thing can be achieved by right-click  and selecting mask to below as long as the layer you want to mask is directly below.

[markw]

3 hours ago, bethanie said:

As you can see from the image, everything I want in white has been "checker boarded"; only now, I can't work out how to get rid of this checkerboard and actually make it white. I've tried what feels like everything, and even when I export it as a png, it comes up as a weird grey tone (see below). If you have any ideas, please let me know, I know I'm so close! 

The checker pattern isn’t really there! It’s just a way common in graphics apps to indicate that those areas of an image are devoid of content and thus transparent.
Some export image types like .png and .tiff can retain this information but .jpeg files can not and any transparent areas will be “filed” with white.
If you want to have a white background you can turn Off/On easily as needed while working you can add a white layer bellow all other layers in the Layer Stack using the Rectangle Tool and just drag it out across your canvas.
Or go to Document > Transparent Background and un-tick this option. Note if you need transparency in your final exports you will have to turn this option back on again.

Another possible option for removing the “real” paper background would be use; Filters > Colour > Erase White Paper. And then use a Levels adjustment layer on top and a white Rectangle underneath the drawing. See attached.

Oh, and that’s a really good drawing too by the way!

Motorbike-thumb-NewBackground.afphoto.zip

[bethanie]

Thank you so much!! I'm definitely well on my way to getting the hang of it now. 

One more thing though; I have an a4 scanner but some of my work is more A3 size. Does anyone know how to scan an a3 page in two parts on an a4 scanner and join them up seamlessly?

 

Thanks

B

[Alfred]

14 minutes ago, bethanie said:

Does anyone know how to scan an a3 page in two parts on an a4 scanner and join them up seamlessly?

Panorama stitching requires a significant amount of overlap between adjacent images, so you’ll need three parts instead of just two.

[walt.farrell]

32 minutes ago, bethanie said:

Does anyone know how to scan an a3 page in two parts on an a4 scanner and join them up seamlessly?

You could make two scans, create a new A3-sized document, then Place each of the scans into the document, and align them manually. If you could get some overlap that would help with the alignment and with helping them appear seemless when you merge them.