Estimate a number of values on an image including angle, distance, area, perimeter, mean, median, area fraction, center of mass, integrated density, skewness, coordinates, centroid, etc.

you can use draw tools such as line, freehand drawing, rectangle, ellipse, polygon, etc. to precisely measure any segment of an image.

ImageJ

ImageJ is an open-source image analysis software which also provides measurement tool along with several other analysis tools.

IC Measure

IC Measure can measure different parameters including length, area, diameter, angle, etc., in a particular image.

CMEIAS ImageTool

CMEIAS ImageTool is an image analysis software which is primarily used in microbial ecology field.

JMicroVision

JMicroVision is an image analysis software which lets you examine, quantify, and measure different aspects of digital images.

ER Viewer

ER Viewer is an image measurement software that provides a dedicated measure tool and can open formats like JPEG, PNG, BMP, TIFF, etc.