contrast

I need to adjust screen brightness/contrast by using Python. It will be a function in my code and it will be run when user presses a key, else script won't change the brigness/contrast. How can i make it in Python? Thank you very much I found what looks like a Linux-specific recipe here . For windows I think you need to find out what function you need to call in which dll (probably driver-specific) and use ctypes to make the required call. This is something that is OS-specific and probably not doable without system-specific bindings. dridk I m using the equation define here . So, to adjust

I would like to know the difference between contrast stretching and histogram equalization . I have tried both using OpenCV and observed the results, but I still have not understood the main differences between the two techniques. Insights would be of much needed help. Lets Define Contrast first, Contrast is a measure of the “range” of an image; i.e. how spread its intensities are. It has many formal definitions one famous is Michelson’s: He says contrast = ( Imax - Imin )/( Imax + I min ) Contrast is strongly tied to an image’s overall visual quality. Ideally, we’d like images to use the

I'm using OpenCV to process some images, and one of the first steps I need to perform is increasing the image contrast on a color image. The fastest method I've found so far uses this code (where np is the numpy import) to multiply and add as suggested in the original C-based cv1 docs : if (self.array_alpha is None): self.array_alpha = np.array([1.25]) self.array_beta = np.array([-100.0]) # add a beta value to every pixel cv2.add(new_img, self.array_beta, new_img) # multiply every pixel value by alpha cv2.multiply(new_img, self.array_alpha, new_img) Is there a faster way to do this in Python?

I've been attempting to perform an ANOVA in R recently on the attached data frame. My question revolves around the setting of contrasts. My design is a 3x5 within-subjects design. There are 3 visual conditions under 'Circle1' and 5 audio under 'Beep1'. Does anyone have any idea how I should set the contrasts? This is something I'm unfamiliar with as I'm making the transition from point and click stats in SPSS to coded in R. Thanks for your time Data file: Nathaniel Payne Reiterating my answer from another stackoverflow question that was flagged as similar , since you didn't provide any code,

I don't know much about color composition, so I came up with this algorithm that will pick a background color based on the font color on a trial an errors basis: public class BackgroundFromForegroundColorConverter : IValueConverter { public object Convert(object value, Type targetType, object parameter, CultureInfo culture) { if (!(value is Color)) return value; Color color = (Color)value; if (color.R + color.G + color.B > 550) return new SolidColorBrush(Colors.Gray); else if (color.R + color.G + color.B > 400) return new SolidColorBrush(Colors.LightGray); else return new SolidColorBrush

I've been writing an image processing program which applies effects through HTML5 canvas pixel processing. I've achieved Thresholding, Vintaging, and ColorGradient pixel manipulations but unbelievably I cannot change the contrast of the image! I've tried multiple solutions but I always get too much brightness in the picture and less of a contrast effect and I'm not planning to use any Javascript libraries since I'm trying to achieve these effects natively. The basic pixel manipulation code: var data = imageData.data; for (var i = 0; i < data.length; i += 4) { //Note: data[i], data[i+1], data[i