Now I am doing a project about image processing. I want to check if there is any white grease on the
surface of a white part.
My method is to capture the image of part containing white grease and then process the image
to check if there is any white grease.
The problem is that the color of part and grease are almost the same (about 99%).
Therefore, I can't separate them and can't detect the grease.
Could you suggest me some ways/methods to check the white grease on the white part?
Maybe something like what kind of light, how to set up light, etc...
Thanks!
Related
I am struggling with the fuzzy selection tool in gimp - try to make the dark part in the picture black while retaining the dark parts below the light border - any advice how to achieve that?
Not with the fuzzy selection or the color selection :)
Very often the best way is to use the image itself (or a copy). If I understand you, you want to select the top dark part (which is many shades of grey), but not the bottom one. In practice we want an image where the selected parts are white and the un-selected are black, so
duplicate the layer
Color>Desaturate (if the image has colors)
Color>Invert
Filters>Blur>Gaussian blur (around 12px in the image you show). In Gimp 2.10, the median blur can also give interesting results)
Use Threshold to make the white very white and the black very. Use the threshold value that keeps a continuous black line across the picture
Bucket fill the lower white part with black (in Gimp 2.10.10 you can use the new Fill by line art detection option of the bucket
Open the Channels list, right click on any f the R, G or B channels and Channel to selection.
Back to the Layers list, hide or delete the work layer, and select the initial layer to continue.
Using the selection with the Curves tool to set the black and white points on the top part:
Simple I have UIImageView icon with two people and it looks like this:
but when I set tintColor to red it looks like this:
Is there any way to avoid covering every non zero-alpha pixel? I need to show the tie really there. One time I need people red, other time green.
The icon is simple png file. Rounded circle is simple background color of UIImageView. So the part of the image with tie cannot be zero-alpha.
Is there any way to achieve such effect WITHOUT creating images for every color?
This was similar to another idea I had been playing around with, so I did a little more fiddling...
Starting with these 3 images:
and then using them as .withRenderingMode(.alwaysTemplate) to give the desired colors... and then layering them via CALayer to get:
and an "exploded" view for clarity...
Create an image where the "people" are 100% transparent - effectively "holes" in the image.
Set the background color of the UIImageView to be the "fill" color.
You can still mask it with a circle (CAShapeLayer, for example), if you don't want a white bounding-box as part of the image.
Original images:
https://i.stack.imgur.com/eFrmB.png
https://i.stack.imgur.com/2GNDX.png
Use the CISpotColor filter:
https://developer.apple.com/library/content/documentation/GraphicsImaging/Reference/CoreImageFilterReference/#//apple_ref/doc/filter/ci/CISpotColor
This allows you to specify a color in your image that is to be changed into another color. Thus, since you know the original color of the tie and the background, you can change either of them, or both, in a single move.
I have a .tiff video file with growing fibers that look like the image below
Now
imagine that this fiber will constantly grow and shrink in a straight line. Now I'd like to somehow crop out the region of the video that contains just the fiber with, for example, a black background image.
Now when I play the video I'd like to just see the growing fiber region of the video with the black background everywhere else.
Question: Is there a way to preform a "custom" crop of irregular shaped objects in ImageJ?
If you don't know if ImageJ can do this sort of image processing any other software options are welcome.
Thanks for any help
Yes, you can do this in ImageJ. If you can find a threshold method that captures your fiber, you can turn that into a selection (ROI), and then Clear Outside to turn everything else black:
Image > Adjust > Threshold and choose the threshold, or use one of the automatic methods. But don't apply the threshold!
Edit > Selection > Create Selection (turns the thresholded area into an ROI)
Edit > Clear Outside (makes the background black -- assuming you have set your background color to black)
If you want to make the window smaller, you can do Image > Crop with the selection active. This will crop the image to the rectangular bounding box of the ROI. But this size will vary according to the size of the fiber. So you might want to do this when the fiber is at its largest.
I have been working with OpenGL in iOS, and setting the colors with glColor4f(r,g,b,a) and then drawing my own color on a white UIImageView. I basically have a brush, which is then moved around my user's touch, and then it paints the color onto the canvas. But this color needs to be water paint (like smudged color)
Does anyone understand/knows how to get a water color like this app does, and how the background UIImageView has a texture on it?
https://itunes.apple.com/us/app/hello-watercolor/id539414526?mt=8
or checkout water paint in this. http://www.fiftythree.com/paper
I created a bounty on this as I am really having a hard time to grasp how to derive such smooth flowing colors out of the normal colors. Even if you guys point me in the right direction, or to some sample code on how I can get the effect of water-paint, it would be really helpful ^_^
And as a bonus, it would be also be helpful if you can point out to me how to get canvas on which it is painted on looks realistic, and blended with the paint? Does Blending/GLSL have to do with any of this?
Is there any sample project on this?
If you are still struggling with the basics of getting realistic looking water colors working, you may want to experiment/prototype in photoshop first.
http://www.zoepiel.com/tutorials/watercolor/ shows some very effective tricks for creating watercolor images with simple tools.
The most interesting one is to multiply a group of watercolor layers with a greyscale watercolor paper image. The texture of the paper makes some parts remain white, and other parts saturate with color, just like real watercolor.
Each layer remains 'wet' in the sense that the colors within it blend, but the layers are 'dry' with respect to each other.
She also explains some of her brush and blur settings and shows what they do.
Once you can produce the desired effect in photoshop, you'll have clear specifications of what you want to do and you'll be quite a bit closer to programming it out.
Looking at the examples you posted, it looks like they are using a simple Gaussian Blur with a radius of double your brush size. This may be an incomplete solution, but it's at least the first level.
For example, I have a transparent png file, the shape is a car.
In the png file, I only draw the white border shape.
Outside and inside the border are all transparent.
I want to use actionscript3 code to show the car object with different color, it means only fill color inside the border, and for the outside of the border, keep transparent.
How to do that?
So far, the simplest workaround is to prepare many images with PhotoShop, but it's not good enough for me. When I have many shapes and use many colors, I've to prepare many many images.
Add more details:
(Because I'm using white border, you may not see the basic png file if your background of browser is white)
Change my boarder of shape to black, hope this is helpful to understand my question.
Since you're working with loaded images/pixels you can make use of BitmapData's floodFill() which pretty much does what you need. There's an example in bellow the method description as well.
It does pretty much what you need, although in some cases it might not be perfect. It's worth having a look at Jan's optimizing the floodFill() method article which goes more in depth.
A simple solution is to use multiple layers. The top layer would contain just the border. The lower layer would contain just the car with no border. You can adjust the colour of the car layer using a ColorTransform or ColorMatrixFilter.