Herein, the radiation response uniformities of six types of charge-coupled devices and complementary metal-oxide-semiconductor image sensors are studied and compared. Irradiation experiments are performed to investigate the average incremental pixel values and nonuniformities of radiation response signals in different regions of the pixel array. The radiation response uniformities of the global pixel array, regional pixels, and typical pixels in various solid-state image sensors are mainly studied. Results show that the incremental pixel value of the frame image under a steady-state gamma-ray irradiation is not a fixed value, and the uniformity of the radiation response signal in each region of pixel array is not affected by the radiation dose rate. For the same image sensor, the distribution of the radiation response signal in any frame image is the same as the radiation response distribution of any pixel, which is from the pixel array, in the multi-frame image. However, there is a deviation in the statistical results across the typical pixels, regional pixels, and global pixel array due to the difference of the sensor background noise. This study provides a theoretical basis and data support for improving the technology of gamma-ray radiation detection based on image sensors and realizing real-time radiation detection without shading.