IOS app for programmable camera
Introduction
Programmable cameras
Our Project
Methodology
Filters using GPUImage library
Histogram and histogram equalization
Image Histograms: Histograms are graphical representations of tonal and luminance distributions in an image. Inspecting histograms of live preview in a camera can help the photographers to adjust the exposure values of their cameras. Also, the RGB histograms can be used as a guide to selectively adjust exposure for different colors. You can make sure that you are not losing details by underexposing or overexposing certain colors. That's why we incorporated the live histogram feature into our app. The GPUImage library provides APIs by which histograms of images can be extracted. We used the APIs GPUImageHistogramFilter and GPUImageHistogramGenerator to extract a histogram and plot it. After extracting the histogram image, we blend it into the live preview image using GPU blend filter. The screenshots are attached.
Histogram equalization and histogram matching: Equalizing a histogram is a technique that is used to adjust pixel intensities to enhance contrast. It's a transformation by which the image pixel intensities (often ranging from 0 - 256) are normalized and redistributed. In a grayscale image or a monotone image, this redistribution is a