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Background-erasing individual pixels?


P

Pixeleraser

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I have now devoted several hours just trying to figure out what first seemed like it should be a pretty basic task in Photoshop but which has now proved a daunting endeavor.

Two problems:

1) Deleting background pixels completely (meaning erasing it with one click)
and

2) Deleting them individually without screwing with contiguous pixels (their colors) at all

When using the regular eraser (not background eraser), I just set it to "block", and it is easy to take out pixels one by one completely. It doesn't just fade them incrementally, but they disappear in one click, and I can easily pick the exact pixel I want to erase.
But when I switch to the background eraser, this becomes impossible. Unless I approach the pixels from the edge, the eraser starts erasing 4 at a time, and it doesn't delete them completely. I have to go over the area several times before they go away completely.

Is there really no way whatsoever to erase the background like I easily can with a layer? Should I really have to spend a bunch of money on a new piece of software (assuming there even is one that can do this)?

Photoshop can do amazing things, but some things that seem really fundamental to me often turn out to be fiendishly complex.
 
I really don't understand your question. If you're trying to delete the background the selection process depending on how intricate the images is, is always going to be a factor not just your eraser tool(s) that do the work selection process is key, but like I said I may not understand your question
 
I never erase any pixels....as I tend to lose a few.

I duplicate and mask.....the closer I work the better it gets

And the matter of 4 pixels vs 1....is your "brush" shape rounded? I use a triangular or square "shaped brush" for tight work ?...And check hardness ?
 
Mike's joke about not erasing pixels is right on the mark.

I haven't used the eraser tool for years and I have spent at least an hour or so per day using PS for probably the past decade. As Mike suggested, the more modern, and more versatile way is to put a mask on the layer. Where the mask is black that layer is not seen AT ALL. Where it is white, the background is not seen AT ALL. If the mask has sharp edges, there is no perturbation of surrounding pixels.

If you use a layer mask in this way, you accomplish exactly what you asked for.

In addition, both the flexibility of the process and its efficiency are greatly increased. It's more flexible than either eraser tool because (again, as Mike said), if you mess up, you simply change the layer mask. In fact, you can do this as many times as you want because the underlying data has not been touched.

It's more time efficient than the eraser tool because you can now use any of dozens of highly developed selection techniques to define and separate the foreground from the background, and then fill in the appropriate areas of the mask with either white, black, or, in many cases something in-between.

HTH,

Tom M
 
Thanks guys. I haven't used the masking tool before, and though it certainly works, in my case since I just wanted to delete a handful of pixels, I think the eraser tool would have been simpler. Though maybe I am just not doing it the right way.
 
As said above, and you can learn from the advice of experienced, skilled PS users, the eraser tool is destructive. If you are going to use it, at least duplicate your original layer first and turn the eye off so it is invisible. That way, if you make a mistake, you still have the original data. As stated above. With a mask, you merely use the brush tool in the same way that you would use the eraser tool. The difference is that if you make a mistake, you don't have to laboriously go through history states to back up and correct them, assuming you even have enough history states created to do so (go to preferences to change this). With a mask, if you make a mistake using the black to erase, you go back and use white to retrieve it so to speak, or vice versa.

You can, as Tom said, use any number of good selection tools to select either the background of the subject(s). Then you can use the refine edge option (or mask and use the refine mask option) to smooth and even contract the edge to get rid of BG pixels. You will always need to zoom in and check your edges to clean them up. It is the rare shopper who can get perfect edges every time. But this method is very time-saving compared to using the undependable BG eraser (IMO). The best tool for making intricate or crucial selections is the pen tool. It is also the best way to get clean, BG pixel free edges. But even this method needs follow-up to be sure those outlines are as clean as you would like them to be.

Other selection tools that have their place are the lasso tools, select color range, and the quick select. Some people prefer the magic wand and in some cases it works, but I find the quick select easier to use. For example, the polygonal lasso is very good for straight-line geometric shapes, such as squares. I often use the regular lasso to help refine my mask when a brush might not be as effective. But I try to make my initial selection as true to the subject as I can and eliminate the need for tons of clean-up.

Good luck with your work, but give serious consideration to forgetting the eraser tool even exists. It is for the total novice and at some point, it is time to move on from that! :devilish:
 
Pixeleraser said:
Thanks guys. I haven't used the masking tool before, and though it certainly works, in my case since I just wanted to delete a handful of pixels, I think the eraser tool would have been simpler. Though maybe I am just not doing it the right way.
Click to expand...

You are using it correctly.....BUT you will lose some, I wish that never happened, but it does, all too quick. Good Luck with your removals!
 
Thanks again. I did manage to erase using the masking feature as per above suggestions, but for some reason it is not working for me today. Any ideas what I might be doing wrong? When I click on the pixels I want to delete, nothing happens. Same thing if I use the marquee tool and select an area to delete. Nothing happens. Ideas?
 
Glad you got it squared away. If you feel like it, we would love to see some examples of the results of this.

Best regards,

Tom
 
Tom Mann said:
Glad you got it squared away. If you feel like it, we would love to see some examples of the results of this.

Best regards,

Tom
Click to expand...

Sure. I have rounded off the left side of this navigation bar button by deleting individual pixels. Since it is so small, I figured I'd get more precision by erasing them individually rather than using the vector tool.

Navbar_3_01.jpg

I am a novice with Photoshop, and I am sure eventually doing things like this will seem easy and natural, but it still sort of bothers me that the background eraser tool doesn't readily let me do things like this. Either way, I appreciate everyone's help.
 
Don't be bothered by it or with it! Try other selection tools, like quick select.

It looks by the way as if the left curved edge is very rough and pixellated. My suggestion would be to make a spherical shape with the shape tool set to paths; position your button or transform and move, resize, etc. the selection if necessary, then fill it (I suggest you use a separate layer for this in case you have to adjust. Once you're satisfied, merge the two, or copy merge if you want to keep the original two layers so can make a change later, if necessary.
 
Pixeleraser said:
Sure. I have rounded off the left side of this navigation bar button by deleting individual pixels. Since it is so small, I figured I'd get more precision by erasing them individually rather than using the vector tool.

View attachment 31172

I am a novice with Photoshop, and I am sure eventually doing things like this will seem easy and natural, but it still sort of bothers me that the background eraser tool doesn't readily let me do things like this. Either way, I appreciate everyone's help.
Click to expand...

As we ALL were , and in some areas still are :redface: The neat thing about PS is as you will discover, is a multitude of different ways to get to the end result...and ALL WORK...and are correct. I for one never used masks until I had to re do a "simple" selection....I realized that I had removed a part of the image...that I didn't need , until after it was gone :banghead:

I then started using masks for everything in my PS workflow...down the road, I learned that it was saving me time and now using a Wacom my masks are a lot crisper, and everything looks better

As far as more precision, vector shapes will always give a crisper edge when resizing vs raster....BUT don't go off track.

DO as you feel the most comfortable, Learn and be open to new ways in PS, Enjoy PS and the forum!
 
ibclare said:
Don't be bothered by it or with it! Try other selection tools, like quick select.

It looks by the way as if the left curved edge is very rough and pixellated. My suggestion would be to make a spherical shape with the shape tool set to paths; position your button or transform and move, resize, etc. the selection if necessary, then fill it (I suggest you use a separate layer for this in case you have to adjust. Once you're satisfied, merge the two, or copy merge if you want to keep the original two layers so can make a change later, if necessary.
Click to expand...

Yes, it does have a somewhat pixellated appearance, but the image is shown at 1:1 scale, and every edge is no more than one pixel in size, so as long as I don't make the button bigger, is this really going to change anything? Unless just fading the pixels along the side gives it a smoother look (?). To my knowledge there is no way to color fill just some percentage of a pixel.
 
Pixeleraser said:
Yes, it does have a somewhat pixellated appearance, but the image is shown at 1:1 scale, and every edge is no more than one pixel in size, so as long as I don't make the button bigger, is this really going to change anything? Unless just fading the pixels along the side gives it a smoother look (?). To my knowledge there is no way to color fill just some percentage of a pixel.
Click to expand...

Try this,

Go to Image>Image Size. Increase the resolution, say from 72 to 300 (or whatever you wish) but make sure that you set the Pixel Dimensions (upper box) to 100 % (if the width and height are linked you need to do this for just one of them), and hit enter. Duplicate the layer and turn the duplicated layer off (you may or may not need this layer). Now, go to Filters>Blur>Gaussian Blur and blur your image a bit. At this point use the Magic Wand to select the body of your button (adjust the sensitivity of the wand so that about 1/2 of the blurred area around the button is included in the selection). Fill this selection with your buttons colour. Now invert the selection and hit delete (or fill it with your background colour). If you need crisp internal detail, or if you have other colours in the interior of the button you can copy the required area of the button from the duplicated layer and fit the copied area on top of the modified button.

I use this technique a lot to reduce or eliminate the stair steps often encountered on angeled or curved edge sections of line drawings. You may find it useful for the work you are doing.
 
Bgood - That's a very nice anti-aliasing technique. I rarely ever see it described, but it's important for people to have it in their tool kit. Personally, I'm lazy and tend to use Power Retouche Pro's Anti-aliasing plugin, but still occasionally use the method you describe if I need more control.

Thanks,

Tom
 
bgoodman4 said:
Try this,

Go to Image>Image Size. Increase the resolution, say from 72 to 300 (or whatever you wish) but make sure that you set the Pixel Dimensions (upper box) to 100 % (if the width and height are linked you need to do this for just one of them), and hit enter. Duplicate the layer and turn the duplicated layer off (you may or may not need this layer). Now, go to Filters>Blur>Gaussian Blur and blur your image a bit. At this point use the Magic Wand to select the body of your button (adjust the sensitivity of the wand so that about 1/2 of the blurred area around the button is included in the selection). Fill this selection with your buttons colour. Now invert the selection and hit delete (or fill it with your background colour). If you need crisp internal detail, or if you have other colours in the interior of the button you can copy the required area of the button from the duplicated layer and fit the copied area on top of the modified button.

I use this technique a lot to reduce or eliminate the stair steps often encountered on angeled or curved edge sections of line drawings. You may find it useful for the work you are doing.
Click to expand...

Thanks! I am working on a big project and haven't had time to try this, but it is great that you are sharing it, and I may decide to do it later. The rounded portion actually overlaps a dark shadow, so it's not that noticeable.
 
Pixeleraser said:
Thanks! I am working on a big project and haven't had time to try this, but it is great that you are sharing it, and I may decide to do it later. The rounded portion actually overlaps a dark shadow, so it's not that noticeable.
Click to expand...

No problem, if you have any questions when you do get to it by all means post them here I I will do my best to clarify.
 
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