pixelchecksum newbie question

[awayne]

I am working with pixel checksums and when I have a rectangle over the same image text with same sized rectangle I am getting different checksum values when I move the text image to different areas of my screen??

Is this normal.  Maybe I need to be doing something else or like the example indicates are PixelCheckSum best used to detect something has changed on the screen rather than whats on the screen.

 

[JohnOne]

Everything visible will affect checksum, background included.

[awayne]

johnone thanks for the reply this is the same exact background and image though just in a different location now and my capture size is the same so I am only getting the image that is just a black background and text.

I just want to clarify so the checksum value will also change if it is in a different location on the screen even if it is the same exact thing being capture?

[Palestinian]

Maybe you should post your code?

From my simple understanding on PixelChecksum, it checks coordinats on your screen, it doesn't follow your desired window around, it scans fixed coordinates, so if you change the location of the window that you want to use the PixelChecksum on, you have to change the x,y coordinates in your script according

[awayne]

so if I am trying to scan an image at x and y and i move it to x and y as long as I am checksuming "EXACTLY" the same image again and only that image the checksum values should be the same??  I know I would have to change the coordinates to capture the image checksum again.

[JohnOne]

johnone thanks for the reply this is the same exact background and image though just in a different location now and my capture size is the same so I am only getting the image that is just a black background and text.

I just want to clarify so the checksum value will also change if it is in a different location on the screen even if it is the same exact thing being capture?

If it is working on the exact same image and area then it should be the same.

[awayne]

ok my next question then is there a tool that will give precision coordinates or I could try to code one.

what i have is a bunch of text on a black background and would like to use pixelchecksum and capture the values and if i see this text again capture the value again but the text on black background will be in a different location on the screen

[awayne]

I guess for the purpose of what I am wanting to do is create a crosshair that is a rectangle and be able to move the rectangle around and a way to capture the rectangle top left and bottom right and turn this into the PixelCheckSum Coordinates just wondering what would be the best avenue to program such a tool or if one already exist

[Palestinian]

Post your scripting attempts and what you have so far

[JohnOne]

It'd have to be pixel perfect positioning.

Thought about OCR?

[awayne]

JohnOne I have thought about OCR however if I can get done and there is a way to tell if four coordinates are going to be cover the same amount of area if my black background and then text is in another area of the screen and i say.

if $checksumvalue is located at some four coordinates then do something.

Is there a way to tell if the four PixelCheckSum values have the same area size as the original grab for the variable??

[JohnQSmith]

It'd have to be pixel perfect positioning.

 

Also, if you have font smoothing (i.e. ClearType) enabled, sub-pixel rendering might be different on one location of the screen as compared to another.